CVE-2021-34557

Description

XScreenSaver 5.45 can be bypassed if the machine has more than ten disconnectable video outputs. A buffer overflow in update_screen_layout() allows an attacker to bypass the standard screen lock authentication mechanism by crashing XScreenSaver. The attacker must physically disconnect many video outputs.

Related CPE's

References

https://github.com/QubesOS/qubes-xscreensaver/blob/master/0001-Fix-updating-outputs-info.patch

https://github.com/QubesOS/qubes-issues/issues/6595

https://github.com/QubesOS/qubes-secpack/blob/master/QSBs/qsb-068-2021.txt

https://www.openwall.com/lists/oss-security/2021/06/05/1

[oss-security] 20210611 Re: XScreenSaver 5.45: Disconnecting a video output can cause XScreenSaver to crash and unlock

CvssV3 impact

CvssV2 impact