CVE-2022-25235
Published: 16 February 2022
Summary
CVE-2022-25235 is a critical-severity Improper Encoding or Escaping of Output (CWE-116) vulnerability in Debian Debian Linux. Its CVSS base score is 9.8 (Critical).
Operationally, ranked in the top 6.4% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
Deeper analysis
CVE-2022-25235 affects xmltok_impl.c in Expat (libexpat) versions before 2.4.5. The component fails to perform sufficient validation of character encodings, including checks that a UTF-8 character is valid in its specific context, which corresponds to CWE-116.
An unauthenticated attacker can supply a crafted XML document over the network and trigger the flaw without user interaction. Successful exploitation yields full compromise of confidentiality, integrity, and availability on the affected system, as reflected in the CVSS 9.8 base score.
Advisories and vendor notices direct users to upgrade to libexpat 2.4.5 or later. Patches referenced in the GitHub pull request and distribution lists such as Debian LTS and Fedora eliminate the missing encoding checks; Siemens and Openwall postings similarly recommend applying the updated package versions.
The EPSS score reached a peak of 0.1332 with a current value of 0.1103.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2022-29933
Vulnerability details
xmltok_impl.c in Expat (aka libexpat) before 2.4.5 lacks certain validation of encoding, such as checks for whether a UTF-8 character is valid in a certain context.
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Validating that output matches expected content directly mitigates failures to properly encode or escape data for its destination context.