CVE-2022-2309

7.5 HIGH
Published: July 05, 2022 Modified: November 04, 2025

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.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://github.com/lxml/lxml/commit/86368e9cf70a0ad23cccd5ee32de847149af0c6f
Source: security@huntr.dev
Patch Third Party Advisory
https://huntr.dev/bounties/8264e74f-edda-4c40-9956-49de635105ba
Source: security@huntr.dev
Exploit Issue Tracking Patch Third Party Advisory
https://security.gentoo.org/glsa/202208-06
Source: security@huntr.dev
Third Party Advisory
https://security.netapp.com/advisory/ntap-20220915-0006/
Source: security@huntr.dev
Third Party Advisory
https://github.com/lxml/lxml/commit/86368e9cf70a0ad23cccd5ee32de847149af0c6f
Source: af854a3a-2127-422b-91ae-364da2661108
Patch Third Party Advisory
https://huntr.dev/bounties/8264e74f-edda-4c40-9956-49de635105ba
Source: af854a3a-2127-422b-91ae-364da2661108
Exploit Issue Tracking Patch Third Party Advisory
https://security.gentoo.org/glsa/202208-06
Source: af854a3a-2127-422b-91ae-364da2661108
Third Party Advisory
https://security.netapp.com/advisory/ntap-20220915-0006/
Source: af854a3a-2127-422b-91ae-364da2661108
Third Party Advisory

13 reference(s) from NVD

Quick Stats

CVSS v3 Score
7.5 / 10.0
EPSS (Exploit Probability)
0.9%
75th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

xmlsoft fedoraproject lxml