VulnerabilityModified
CVE-2021-34557
XScreenSaver 5.45 can be bypassed if the machine has more than ten disconnectable video outputs.
MEDIUM 4.6EPSS 0.48%
Does this matter?
Lower severity and a low EPSS score (0.48%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 4.6 MEDIUMCVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.48% probability · 40th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-120
- Affected
- xscreensaver project/xscreensaver · fedoraproject/fedora
- Source
- cve@mitre.org
References
- http://www.openwall.com/lists/oss-security/2021/06/11/1Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/07/06/2Exploit, Mailing List, Third Party Advisory
- https://github.com/QubesOS/qubes-issues/issues/6595Issue Tracking, Third Party Advisory
- https://github.com/QubesOS/qubes-secpack/blob/master/QSBs/qsb-068-2021.txtExploit, Third Party Advisory
- https://github.com/QubesOS/qubes-xscreensaver/blob/master/0001-Fix-updating-outputs-info.patchPatch, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TC4QB7TRS4GS7LDXQQ4PC6J3LVFJYISV/
- https://www.openwall.com/lists/oss-security/2021/06/05/1Exploit, Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/06/11/1Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/07/06/2Exploit, Mailing List, Third Party Advisory
- https://github.com/QubesOS/qubes-issues/issues/6595Issue Tracking, Third Party Advisory
- https://github.com/QubesOS/qubes-secpack/blob/master/QSBs/qsb-068-2021.txtExploit, Third Party Advisory
- https://github.com/QubesOS/qubes-xscreensaver/blob/master/0001-Fix-updating-outputs-info.patchPatch, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TC4QB7TRS4GS7LDXQQ4PC6J3LVFJYISV/
- https://www.openwall.com/lists/oss-security/2021/06/05/1Exploit, Mailing List, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.