cbcvebase.
CVE-2022-26485
published 2022-12-22

CVE-2022-26485: Removing an XSLT parameter during processing could have lead to an exploitable use-after-free. We have had reports of attacks in the wild abusing this flaw…

PriorityP183high8.8CVSS 3.1
AVNACLPRNUIRSUCHIHAH
KEVITWEXPLOIT
CISA Known Exploited Vulnerabilitydue 2022-03-21
Exploited in the wild
EPSS
14.26%
96.2th percentile
Removing an XSLT parameter during processing could have lead to an exploitable use-after-free. We have had reports of attacks in the wild abusing this flaw. This vulnerability affects Firefox < 97.0.2, Firefox ESR < 91.6.1, Firefox for Android < 97.3.0, Thunderbird < 91.6.2, and Focus < 97.3.0.

Affected

20 ranges
VendorProductVersion rangeFixed in
debianfirefox< firefox 99.0-1 (sid)firefox 99.0-1 (sid)
debianfirefox-esr< firefox 99.0-1 (sid)firefox 99.0-1 (sid)
debianthunderbird< firefox 99.0-1 (sid)firefox 99.0-1 (sid)
mozillafirefox< 91.6.191.6.1
mozillafirefox< 97.0.297.0.2
mozillafirefox< 97.3.097.3.0
mozillafirefox
mozillafirefox>= 0 < 97.0.2+build1-0ubuntu0.18.04.197.0.2+build1-0ubuntu0.18.04.1
mozillafirefox>= 0 < 97.0.2+build1-0ubuntu0.20.04.197.0.2+build1-0ubuntu0.20.04.1
mozillafirefox>= unspecified < 97.0.297.0.2
mozillafirefox_esr>= unspecified < 91.6.191.6.1
mozillafirefox_focus< 97.3.097.3.0
mozillafirefox_for_android>= unspecified < 97.3.097.3.0
mozillafocus>= unspecified < 97.3.097.3.0
mozillathunderbird< 91.6.291.6.2
mozillathunderbird>= 0 < 1:91.6.2-1~deb11u11:91.6.2-1~deb11u1
mozillathunderbird>= 0 < 1:91.6.2-11:91.6.2-1
mozillathunderbird>= 0 < 1:91.6.2-11:91.6.2-1
mozillathunderbird>= 0 < 1:91.6.2-11:91.6.2-1
mozillathunderbird>= unspecified < 91.6.291.6.2

Detection & IOCsextracted from sources · hover to see the quote

commanda2.removeParameter(null, 'test00');
pathdom/xslt/xslt/txMozillaXSLTProcessor.cpp
  • The exploit triggers a heap-use-after-free in txVariable::Convert (txMozillaXSLTProcessor.cpp:1361) by calling XSLTProcessor.removeParameter() from within a Symbol.toPrimitive callback during transformToDocument execution. Detect JavaScript that creates an XSLTProcessor, sets a parameter with an object having a custom [Symbol.toPrimitive] that calls removeParameter(), then calls transformToDocument().
  • The PoC exploit pattern involves: (1) new XSLTProcessor(), (2) setParameter() with an object whose Symbol.toPrimitive calls removeParameter(), (3) transformToDocument(). Monitor for this JS API call sequence in browser telemetry or content process sandboxing logs.
  • This vulnerability is confirmed exploited in the wild (CISA KEV). Prioritize detection on Firefox < 97.0.2, Firefox ESR < 91.6.1, Firefox for Android < 97.3.0, Thunderbird < 91.6.2, and Focus < 97.3.0.
  • The exploit type is classified as Render RCE, meaning exploitation occurs in the renderer/content process. Sandbox escape may follow; monitor for unexpected child process spawning from firefox.exe or thunderbird.exe renderer processes.
  • ·The Bugzilla PoC is a minimal proof-of-concept (MINIPOC) demonstrating the UAF trigger; real in-the-wild exploits likely use obfuscated or more complex variants of this JS pattern.
  • ·Red Hat Enterprise Linux 9 packages for firefox and thunderbird are listed as 'Not affected', so detection/patching priority should focus on RHEL 6/8 and other affected platforms.

CVSS provenance

nvdv3.18.8HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
osv8.8HIGH
vulncheck8.8HIGH
cisa8.8HIGH
vendor_debian8.8HIGH
vendor_redhat8.8HIGH
vendor_ubuntu8.8HIGH
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