CVE-2022-2309

HIGH
Published Jul 5, 20223y ago · Modified Jun 17, 20262w ago
7.5 CVSS 3.1
High
Find Similar
Published Jul 5, 2022 3y ago
Last Modified Jun 17, 2026 2w ago

Description

NULL Pointer Dereference allows attackers to cause a denial of service (or application crash). This only applies when lxml is used together with libxml2 2.9.10 through 2.9.14. libxml2 2.9.9 and earlier are not affected. It allows triggering crashes through forged input data, given a vulnerable code sequence in the application. The vulnerability is caused by the iterwalk function (also used by the canonicalize function). Such code shouldn't be in wide-spread use, given that parsing + iterwalk would usually be replaced with the more efficient iterparse function. However, an XML converter that serialises to C14N would also be vulnerable, for example, and there are legitimate use cases for this code sequence. If untrusted input is received (also remotely) and processed via iterwalk function, a crash can be triggered.

CVSS Details

Base Score
7.5
Exploitability
3.9
Impact
3.6
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

No active exploitation signals — not in CISA KEV and no EPSS score yet.

Exploit & Patch Status
Public Exploit Known
Patch Available

Weaknesses 1

CWE-476 NULL Pointer Dereference Memory Safety

Affected Products 4

VendorProductVersionRange
lxmllxml* <4.9.1
xmlsoftlibxml2*≥2.9.10  –  ≤2.9.14
fedoraprojectfedora36any
fedoraprojectfedora37any

References 7

  • github.com https://github.com/lxml/lxml/commit/86368e9cf70a0ad23cccd5ee32de847149af0c6f
    PatchThird Party Advisory
  • huntr.dev https://huntr.dev/bounties/8264e74f-edda-4c40-9956-49de635105ba
    ExploitIssue TrackingPatchThird Party Advisory
  • lists.debian.org https://lists.debian.org/debian-lts-announce/2024/09/msg00021.html
  • lists.fedoraproject.org https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HGYC6L7ENH5VEGN3YWFBYMGKX6WNS7HZ/
  • lists.fedoraproject.org https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/URHHSIBTPTALXMECRLAC2EVDNAFSR5NO/
  • security.gentoo.org https://security.gentoo.org/glsa/202208-06
    Third Party Advisory
  • security.netapp.com https://security.netapp.com/advisory/ntap-20220915-0006/
    Third Party Advisory

Remediation

  • github.com https://github.com/lxml/lxml/commit/86368e9cf70a0ad23cccd5ee32de847149af0c6f
    PatchThird Party Advisory
  • huntr.dev https://huntr.dev/bounties/8264e74f-edda-4c40-9956-49de635105ba
    ExploitIssue TrackingPatchThird Party Advisory