CVE-2022-2309

Published: 5 July 2022

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.

Priority

Cvss 3 Severity Score

7.5

Score breakdown

Status

Package	Release	Status
libxml2 Launchpad, Ubuntu, Debian	bionic	Not vulnerable (code not present)
	focal	Released (2.9.10+dfsg-5ubuntu0.20.04.5)
	jammy	Released (2.9.13+dfsg-1ubuntu0.2)
	kinetic	Released (2.9.14+dfsg-1ubuntu0.1)
	lunar	Released (2.9.14+dfsg-1.1ubuntu0.1)
	mantic	Not vulnerable (2.9.14+dfsg-1.3)
	trusty	Not vulnerable (code not present)
	upstream	Released (2.10.0,2.9.14+dfsg-1.3)
	xenial	Not vulnerable (code not present)
	Patches: upstream: https://gitlab.gnome.org/GNOME/libxml2/-/commit/5930fe01963136ab92125feec0c6204d9c9225dc
lxml Launchpad, Ubuntu, Debian	bionic	Needs triage
	focal	Needs triage
	impish	Ignored (end of life)
	jammy	Needs triage
	kinetic	Ignored (end of life, was needs-triage)
	lunar	Not vulnerable (4.9.1-1)
	mantic	Not vulnerable (4.9.1-1)
	trusty	Needs triage
	upstream	Released (4.9.1)
	xenial	Needs triage
	Patches: upstream: https://github.com/lxml/lxml/commit/86368e9cf70a0ad23cccd5ee32de847149af0c6f

Severity score breakdown

Parameter	Value
Base score	7.5
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality	None
Integrity impact	None
Availability impact	High
Vector	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

Bugs

https://bugs.launchpad.net/bugs/1996494

Join the discussion

Canonical is offering Expanded Security Maintenance

Canonical is offering Ubuntu Expanded Security Maintenance (ESM) for security fixes and essential packages.

Find out more about ESM ›