Bug 862324 (CVE-2013-4394) - CVE-2013-4394 systemd: Improper sanitization of invalid XKB layouts descriptions (privilege escalation when custom PolicyKit local authority file used)
Summary: CVE-2013-4394 systemd: Improper sanitization of invalid XKB layouts descripti...
Alias: CVE-2013-4394
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
Depends On: 859931
Blocks: 859151
TreeView+ depends on / blocked
Reported: 2012-10-02 15:58 UTC by Jan Lieskovsky
Modified: 2023-05-12 23:46 UTC (History)
3 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Last Closed: 2014-02-12 06:08:02 UTC

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Description Jan Lieskovsky 2012-10-02 15:58:23 UTC
A possibility of unauthorized Xorg X11 Server configuration file modification / injection was found in the way SetX11Keyboard() method of systemd, a system and service manager, performed sanitization of provided X Keyboard Extension (XKB) layouts description (special and control characters were not filtered out from the layout description properly). When the host in question used PolicyKit Local Authority (PKLA) file mechanism to grant group of users the privilege to change XKB settings (instead of default PolicyKit check) and particular local attacker was member of that group, they could use this flaw to inject arbitrary values into the Xorg X11 Server configuration file, possibly leading to escalation of their privileges.

Issue found by Florian Weimer, Red Hat Product Security Team

Comment 9 Vincent Danen 2013-10-01 22:49:28 UTC
This was assigned CVE-2013-4394:


Comment 10 Vincent Danen 2013-10-01 22:50:25 UTC

This issue was discovered by Florian Weimer of the Red Hat Product Security Team.

Comment 12 Huzaifa S. Sidhpurwala 2013-10-04 09:50:57 UTC
This issue has been addressed in the version of systemd as shipped with Fedora 18 and 19. (Current versions are not affected)

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