#VU84372 Out-of-bounds write in X.org Server and Xwayland - CVE-2023-6377

Vulnerability identifier: #VU84372

Vulnerability risk: Low

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

CVE-ID: CVE-2023-6377

CWE-ID: CWE-787

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
X.org Server
Server applications / Other server solutions
Xwayland
Client/Desktop applications / Multimedia software

Vendor: X.org

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a boundary error in the XKB button handler when switching logical input devices. A local user can trigger an out-of-bounds write and execute arbitrary code with elevated privileges.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

X.org Server: 1.7.0 - 21.1.9

Xwayland: 21.0.99.901 - 23.2.2

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External links
http://www.mail-archive.com/xorg-announce@lists.x.org/msg01644.html
http://www.zerodayinitiative.com/advisories/ZDI-24-011/
http://www.zerodayinitiative.com/advisories/ZDI-24-010/

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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.