CVE-2023-5574

Published: 25 October 2023

A use-after-free flaw was found in xorg-x11-server-Xvfb. This issue occurs in Xvfb with a very specific and legacy configuration (a multi-screen setup with multiple protocol screens, also known as Zaphod mode). If the pointer is warped from a screen 1 to a screen 0, a use-after-free issue may be triggered during shutdown or reset of the Xvfb server, allowing for possible escalation of privileges or denial of service.

Notes

Priority reason:
Only affects legacy multiscreen setups with Zaphod

xorg server is actually the xorg-server package
the xorg package only contains docs
xwayland package contains parts of xorg-server
issue does not affected xwayland
This is ZDI-CAN-21213
Due to last minute regressions, the final patches have not yet
been released for this issue.
This issue only affects Xvfb and requires a legacy multi-screen
setup with multiple protocol screens ("Zaphod").

Status

Severity score breakdown

References

• https://www.cve.org/CVERecord?id=CVE-2023-5574
• NVD
• Launchpad
• Debian