CVE-2021-34557: Buffer Overflow
First published: Thu Jun 10 2021(Updated: )
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.
Credit: cve@mitre.org
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Xscreensaver Project Xscreensaver | =5.45 | |
| Fedoraproject Fedora | =33 |
Remedy
https://github.com/QubesOS/qubes-xscreensaver/blob/master/0001-Fix-updating-outputs-info.patch
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Reference Links
- http://www.openwall.com/lists/oss-security/2021/06/11/1
- http://www.openwall.com/lists/oss-security/2021/07/06/2
- https://github.com/QubesOS/qubes-issues/issues/6595
- https://github.com/QubesOS/qubes-secpack/blob/master/QSBs/qsb-068-2021.txt
- https://github.com/QubesOS/qubes-xscreensaver/blob/master/0001-Fix-updating-outputs-info.patch
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/TC4QB7TRS4GS7LDXQQ4PC6J3LVFJYISV/
- https://www.openwall.com/lists/oss-security/2021/06/05/1
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TC4QB7TRS4GS7LDXQQ4PC6J3LVFJYISV/
- collector/nvd-index
- agent/type
- collector/mitre-cve
- source/MITRE
- agent/references
- agent/severity
- agent/author
- agent/weakness
- agent/remedy
- agent/last-modified-date
- agent/tags
- agent/event
- agent/description
- agent/softwarecombine
- agent/first-publish-date
- vendor/xscreensaver project
- canonical/xscreensaver project xscreensaver
- version/xscreensaver project xscreensaver/5.45
- vendor/fedoraproject
- canonical/fedoraproject fedora
- version/fedoraproject fedora/33