UBUNTU-CVE-2021-34557
- Source
- https://ubuntu.com/security/CVE-2021-34557
- Import Source
- https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-34557.json
- JSON Data
- https://api.osv.dev/v1/vulns/UBUNTU-CVE-2021-34557
- Related
- Published
- 2021-06-10T16:15:00Z
- Modified
- 2025-01-13T10:22:34Z
- Severity
-
- 4.6 (Medium) CVSS_V3 - CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
- Summary
- [none]
- Details
-
XScreenSaver 5.45 can be bypassed if the machine has more than ten disconnectable video outputs. A buffer overflow in updatescreenlayout() allows an attacker to bypass the standard screen lock authentication mechanism by crashing XScreenSaver. The attacker must physically disconnect many video outputs.
- References
-
- https://ubuntu.com/security/CVE-2021-34557
- https://www.openwall.com/lists/oss-security/2021/06/05/1
- https://www.openwall.com/lists/oss-security/2021/06/05/2
- 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.cve.org/CVERecord?id=CVE-2021-34557
Affected packages
Ubuntu:Pro:16.04:LTS / xscreensaver
Package
- Name
- xscreensaver
- Purl
- pkg:deb/ubuntu/xscreensaver@5.34-2ubuntu1?arch=source&distro=esm-apps/xenial
Ubuntu:Pro:18.04:LTS / xscreensaver
Package
- Name
- xscreensaver
- Purl
- pkg:deb/ubuntu/xscreensaver@5.36-1ubuntu1?arch=source&distro=esm-apps/bionic
Ubuntu:20.04:LTS / xscreensaver
Package
- Name
- xscreensaver
- Purl
- pkg:deb/ubuntu/xscreensaver@5.42+dfsg1-1ubuntu1?arch=source&distro=focal