CVEvulnerability
CVE-2021-34557
4.6 MEDIUM
Official page ↗
- Status
- Modified
- Published
- 2021-06-10
- Last modified
- 2026-06-17
- Assigner
- [email protected]
- CVSS 3.1 ([email protected])
- 4.6 MEDIUM — CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CVSS 2.0 ([email protected])
- 2.1 LOW — AV:L/AC:L/Au:N/C:N/I:N/A:P
- Weaknesses
- CWE-120
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.
Affected configurations
• xscreensaver project xscreensaver 5.45
• fedoraproject fedora 33
Related
Weakness · CWE (1)
- CWE-120 Buffer Copy without Checking Size of Input weakness
References
- http://www.openwall.com/lists/oss-security/2021/06/11/1 Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/07/06/2 Exploit, Mailing List, Third Party Advisory
- https://github.com/QubesOS/qubes-issues/issues/6595 Issue Tracking, Third Party Advisory
- https://github.com/QubesOS/qubes-secpack/blob/master/QSBs/qsb-068-2021.txt Exploit, Third Party Advisory
- https://github.com/QubesOS/qubes-xscreensaver/blob/master/0001-Fix-updating-outputs-info.patch Patch, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TC4QB7TRS4GS7LDXQQ4PC6J3LVFJYISV/ lists.fedoraproject.org
- https://www.openwall.com/lists/oss-security/2021/06/05/1 Exploit, Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/06/11/1 Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/07/06/2 Exploit, Mailing List, Third Party Advisory
- https://github.com/QubesOS/qubes-issues/issues/6595 Issue Tracking, Third Party Advisory
- https://github.com/QubesOS/qubes-secpack/blob/master/QSBs/qsb-068-2021.txt Exploit, Third Party Advisory
- https://github.com/QubesOS/qubes-xscreensaver/blob/master/0001-Fix-updating-outputs-info.patch Patch, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TC4QB7TRS4GS7LDXQQ4PC6J3LVFJYISV/ lists.fedoraproject.org
- https://www.openwall.com/lists/oss-security/2021/06/05/1 Exploit, Mailing List, Third Party Advisory