CVE-2022-2309
NULL Pointer Dereference allows attackers to cause a denial of service (or application crash).
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (2.63%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 2.63% probability · 85th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-476
- Affected
- lxml/lxml · fedoraproject/fedora
- Source
- security@huntr.dev
References
- https://github.com/lxml/lxml/commit/86368e9cf70a0ad23cccd5ee32de847149af0c6fPatch, Third Party Advisory
- https://huntr.dev/bounties/8264e74f-edda-4c40-9956-49de635105baExploit, Issue Tracking, Patch, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HGYC6L7ENH5VEGN3YWFBYMGKX6WNS7HZ/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/URHHSIBTPTALXMECRLAC2EVDNAFSR5NO/
- https://security.gentoo.org/glsa/202208-06Third Party Advisory
- https://security.netapp.com/advisory/ntap-20220915-0006/Third Party Advisory
- https://github.com/lxml/lxml/commit/86368e9cf70a0ad23cccd5ee32de847149af0c6fPatch, Third Party Advisory
- https://huntr.dev/bounties/8264e74f-edda-4c40-9956-49de635105baExploit, Issue Tracking, Patch, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2024/09/msg00021.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HGYC6L7ENH5VEGN3YWFBYMGKX6WNS7HZ/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/URHHSIBTPTALXMECRLAC2EVDNAFSR5NO/
- https://security.gentoo.org/glsa/202208-06Third Party Advisory
- https://security.netapp.com/advisory/ntap-20220915-0006/Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.