An invalid free in ExprAppendMultiKeysymList in xkbcomp/ast-build.c in xkbcommon before 0.8.1 could be used by local attackers to crash xkbcommon keymap parsers or possibly have unspecified other impact by supplying a crafted keymap file.
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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
| Link | Tags |
|---|---|
| https://security.gentoo.org/glsa/201810-05 | third party advisory vendor advisory |
| https://usn.ubuntu.com/3786-1/ | third party advisory vendor advisory |
| https://github.com/xkbcommon/libxkbcommon/commit/c1e5ac16e77a21f87bdf3bc4dea61b037a17dddb | third party advisory patch |
| https://usn.ubuntu.com/3786-2/ | third party advisory vendor advisory |
| https://lists.freedesktop.org/archives/wayland-devel/2018-August/039232.html | mailing list third party advisory patch |
| https://access.redhat.com/errata/RHSA-2019:2079 | vendor advisory |