{"cve":"CVE-2021-34557","nvd":{"published":"2021-06-10T16:15:08.227","modified":"2026-06-17T03:56:07.123","status":"Modified","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_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":4.6},"cwes":["CWE-120"],"references":["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"],"products":["fedoraproject:fedora","xscreensaver_project:xscreensaver"],"source":"nvd","synced_at":"2026-10-19T21:20:07.141963181+00:00"},"epss":{"cve":"CVE-2021-34557","score":0.0048,"percentile":0.41405,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}