#VU33698 Race condition - CVE-2011-4029

Vulnerability identifier: #VU33698

Vulnerability risk: Low

CVSSv4.0: 2 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/U:Clear]

CVE-ID: CVE-2011-4029

CWE-ID: CWE-362

Exploitation vector: Local

Exploit availability: Yes

Description

The vulnerability allows a local non-authenticated attacker to gain access to sensitive information.

The LockServer function in os/utils.c in X.Org xserver before 1.11.2 allows local users to change the permissions of arbitrary files to 444, read those files, and possibly cause a denial of service (removed execution permission) via a symlink attack on a temporary lock file.

Mitigation
Install update from vendor's website.

External links
https://cgit.freedesktop.org/xorg/xserver/commit/?id=b67581cf825940fdf52bf2e0af4330e695d724a4
https://lists.freedesktop.org/archives/xorg/2011-October/053680.html
https://rhn.redhat.com/errata/RHSA-2012-0939.html
https://secunia.com/advisories/46460
https://secunia.com/advisories/49579

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.