Buffer overflow in Xscreensaver Project
CVE-2021-34557
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.
Vulnerability class: Buffer Overflow
EPSS: 0.005 (38.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 4.6 (Medium). Vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Xscreensaver_project Xscreensaver — versions 5.45
- Fedoraproject Fedora — versions 33
- N/a — versions n/a
Weakness classification (CWE)
References
- cve@mitre.org (Third Party Advisory, x_refsource_MISC, Issue Tracking)
- cve@mitre.org (Exploit, Mailing List, Third Party Advisory, x_refsource_MISC)
- cve@mitre.org (Exploit, Third Party Advisory, x_refsource_MISC)
- cve@mitre.org (Patch, Third Party Advisory, x_refsource_MISC)
- cve@mitre.org (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)
- cve@mitre.org (mailing-list, x_refsource_MLIST, Exploit, Mailing List, Third Party Advisory)
- cve@mitre.org (x_refsource_FEDORA, vendor-advisory)
Frequently asked questions
- What is CVE-2021-34557?
- CVE-2021-34557 is a medium-severity vulnerability in Xscreensaver Project, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 4.6/10. Published 2021-06-10.
- How severe is CVE-2021-34557?
- Medium severity. CVSS v3 base score is 4.6 out of 10.