#VU77450 Out-of-bounds write in libx11 - CVE-2023-3138

Vulnerability identifier: #VU77450

Vulnerability risk: Medium

CVSSv4.0: 4.9 [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2023-3138

CWE-ID: CWE-787

Exploitation vector: Local network

Exploit availability: No

Vulnerable software:
libx11
Other software / Other software solutions

Vendor: xorg.freedesktop.org

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a boundary error within src/InitExt.c in libX11. A remote attacker can send specially crafted data to the server, trigger an out-of-bounds write and perform a denial of service (DoS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

libx11: 1.0.99.1 - 1.8.5

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External links
https://gitlab.freedesktop.org/xorg/lib/libx11/-/commit/304a654a0d57bf0f00d8998185f0360332cfa36c
https://www.openwall.com/lists/oss-security/2023/06/15/2

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the local network (LAN).

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.