Xorg-x11-server: use-after-free in procrenderaddglyphs

Summary

A use-after-free vulnerability was found in the ProcRenderAddGlyphs() function of Xorg servers. This issue occurs when AllocateGlyph() is called to store new glyphs sent by the client to the X server, potentially resulting in multiple entries pointing to the same non-refcounted glyphs. Consequently, ProcRenderAddGlyphs() may free a glyph, leading to a use-after-free scenario when the same glyph pointer is subsequently accessed. This flaw allows an authenticated attacker to execute arbitrary code on the system by sending a specially crafted request.

Timeline

1. Apr 5, 2024, 12:04 PM UTCCVE published
2. Apr 5, 2024, 6:36 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: no · Technical impact: total

3. Nov 20, 2025, 7:19 AM UTCRecord last updated

Affected versions

• xorg-x11-server

  21.1.12

• tigervnc

  Version range not reported

• xorg-x11-server

  Version range not reported

• tigervnc

  Version range not reported

• tigervnc

  Version range not reported

• xorg-x11-server

  Version range not reported

• tigervnc

  Version range not reported

• xorg-x11-server-Xwayland

  Version range not reported

• tigervnc

  Version range not reported

• tigervnc

  Version range not reported

• tigervnc

  Version range not reported

• tigervnc

  Version range not reported

• tigervnc

  Version range not reported

• tigervnc

  Version range not reported

• tigervnc

  Version range not reported

• tigervnc

  Version range not reported

• tigervnc

  Version range not reported

• xorg-x11-server-Xwayland

  Version range not reported

• xorg-x11-server

  Version range not reported

• tigervnc

  Version range not reported

• tigervnc

  Version range not reported

• tigervnc

  Version range not reported

• xorg-x11-server

  Version range not reported

• xorg-x11-server-Xwayland

  Version range not reported

• xorg-x11-server

  Version range not reported

References 18