CVE-2023-0494

A vulnerability was found in X.Org. This issue occurs due to a dangling pointer in DeepCopyPointerClasses that can be exploited by ProcXkbSetDeviceInfo() and ProcXkbGetDeviceInfo() to read and write into freed memory. This can lead to local privilege elevation on systems where the X server runs privileged and remote code execution for ssh X forwarding sessions.

Weakness

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

Potential Mitigations

References

• https://bugzilla.redhat.com/show_bug.cgi?id=2165995
• https://gitlab.freedesktop.org/xorg/xserver/-/commit/0ba6d8c37071131a49790243cdac55392ecf71ec
• https://lists.x.org/archives/xorg-announce/2023-February/003320.html
• https://security.gentoo.org/glsa/202305-30
• https://bugzilla.redhat.com/show_bug.cgi?id=2165995
• https://gitlab.freedesktop.org/xorg/xserver/-/commit/0ba6d8c37071131a49790243cdac55392ecf71ec
• https://lists.x.org/archives/xorg-announce/2023-February/003320.html
• https://security.gentoo.org/glsa/202305-30