#VU99493 Heap-based buffer overflow in X.org Server and Xwayland - CVE-2024-9632

Vulnerability identifier: #VU99493

Vulnerability risk: Low

CVSSv4.0: 5.9 [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-2024-9632

CWE-ID: CWE-122

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 within the XkbSetCompatMap() function in xkb/xkb.c. A local user can pass a specially crafted bitmap to the X.Org server, trigger a heap-based buffer overflow and execute arbitrary code with elevated privileges.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

X.org Server: 21.0.99.1 - 21.1.13

Xwayland: 21.0.99.901 - 24.1.3

---

External links
https://lists.x.org/archives/xorg-announce/2024-October/003545.html
https://gitlab.freedesktop.org/xorg/xserver/-/commit/85b776571487f52e756f68a069c768757369bfe3
https://www.zerodayinitiative.com/advisories/ZDI-24-1453/

---

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.