Out-of-bounds write in Vim - #VU135167

Detailed vulnerability description

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to out-of-bounds write in the SAL sound-folding logic in spell_soundfold_sal() when processing a boundary-length word through soundfold() with a SAL-based spell language active. A local user can supply a crafted boundary-length word to cause a denial of service.

The vulnerable path is only reached under a non-multibyte 8-bit encoding such as latin1, and spell checking must be enabled with a SAL-based language.

Remediation

Sources

• https://github.com/vim/vim/security/advisories/GHSA-m3hf-xcm3-xhm2
• https://github.com/vim/vim/commit/d22ff1c955ff87e8273210eae125aab0e85b6c30