Buffer underflow in Vim - #VU139257

Vulnerability details

The vulnerability allows a remote attacker to read and modify memory outside the bounds of a heap array.

The vulnerability exists due to out-of-bounds write in popup_mark_opacity_zindex() in src/popupwin.c when processing Vim script-created popup windows with the "clipwindow", "opacity", and text property anchor options after the host window is scrolled so the anchor moves above the visible area. A remote attacker can trick the victim into running a crafted Vim script to read and modify memory outside the bounds of a heap array.

The issue is not reachable by opening a file alone, because a modeline cannot call functions.

Affected software

Remediation

External References

• https://github.com/vim/vim/security/advisories/GHSA-pmvp-6rcj-98p4
• https://github.com/vim/vim/commit/975e191dc817d8d00abca7197c4529a417c2f805

Related Security Bulletins

• Buffer underflow in Vim