NVD Vulnerability Detail

CVE-2021-34557

Summary	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.
Publication Date	June 11, 2021, 1:15 a.m.
Registration Date	June 11, 2021, 10 a.m.
Last Update	Nov. 21, 2024, 3:10 p.m.

Affected software configurations

Configuration1		or higher	or less	more than	less than
cpe:2.3:a:xscreensaver_project:xscreensaver:5.45:::::::*

Configuration2		or higher	or less	more than	less than
cpe:2.3:o:fedoraproject:fedora:33:::::::*

Related information, measures and tools

No	URL	タグ
1	http://www.openwall.com/lists/oss-security/2021/06/11/1	Mailing List Third Party Advisory
2	http://www.openwall.com/lists/oss-security/2021/06/11/1	Mailing List Third Party Advisory
3	http://www.openwall.com/lists/oss-security/2021/07/06/2	Exploit Mailing List Third Party Advisory
4	http://www.openwall.com/lists/oss-security/2021/07/06/2	Exploit Mailing List Third Party Advisory
5	https://github.com/QubesOS/qubes-issues/issues/6595	Issue Tracking Third Party Advisory
6	https://github.com/QubesOS/qubes-issues/issues/6595	Issue Tracking Third Party Advisory
7	https://github.com/QubesOS/qubes-secpack/blob/master/QSBs/qsb-068-2021.txt	Exploit Third Party Advisory
8	https://github.com/QubesOS/qubes-secpack/blob/master/QSBs/qsb-068-2021.txt	Exploit Third Party Advisory
9	https://github.com/QubesOS/qubes-xscreensaver/blob/master/0001-Fix-updating-outputs-info.patch	Patch Third Party Advisory
10	https://github.com/QubesOS/qubes-xscreensaver/blob/master/0001-Fix-updating-outputs-info.patch	Patch Third Party Advisory
11	https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TC4QB7TRS4GS7LDXQQ4PC6J3LVFJYISV/
12	https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TC4QB7TRS4GS7LDXQQ4PC6J3LVFJYISV/
13	https://www.openwall.com/lists/oss-security/2021/06/05/1	Exploit Mailing List Third Party Advisory
14	https://www.openwall.com/lists/oss-security/2021/06/05/1	Exploit Mailing List Third Party Advisory

Common Vulnerabilities List

No	CWE	Name	URL
1	CWE-120	古典的バッファオーバーフロー	https://cwe.mitre.org/data/definitions/120.html

JVN Vulnerability Information

XScreenSaver における古典的バッファオーバーフローの脆弱性

Title	XScreenSaver における古典的バッファオーバーフローの脆弱性
Summary	XScreenSaver には、古典的バッファオーバーフローの脆弱性が存在します。
Possible impacts	サービス運用妨害 (DoS) 状態にされる可能性があります。
Solution	ベンダ情報および参考情報を参照して適切な対策を実施してください。
Publication Date	May 11, 2021, midnight
Registration Date	March 8, 2022, 1:51 p.m.
Last Update	March 8, 2022, 1:51 p.m.

Affected System

Fedora Project

Fedora

XScreenSaver project

XScreenSaver 5.45

CVE (情報セキュリティ共通脆弱性識別子)

No	Name	URL
Common Vulnerabilities and Exposures (CVE)
1	CVE-2021-34557	https://www.cve.org/CVERecord?id=CVE-2021-34557
National Vulnerability Database (NVD)
2	CVE-2021-34557	https://nvd.nist.gov/vuln/detail/CVE-2021-34557

CWE (共通脆弱性タイプ一覧)

No	Name	URL
JVNDB
1	CWE-120	https://cwe.mitre.org/data/definitions/120.html

ベンダー情報

No	Name	URL
Fedora Update Notification
1	FEDORA-2021-5af4452ffd	https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/TC4QB7TRS4GS7LDXQQ4PC6J3LVFJYISV/
GitHub
2	Disconnecting a video output can cause XScreenSaver to crash (QSB-068, CVE-2021-34557) #6595	https://github.com/QubesOS/qubes-issues/issues/6595
3	qsb-068-2021.txt	https://github.com/QubesOS/qubes-secpack/blob/master/QSBs/qsb-068-2021.txt

その他

No	Name	URL
関連文書
1	xscreensaver 5.45 crash	https://www.openwall.com/lists/oss-security/2021/07/06/2

Change Log

No	Changed Details	Date of change
1	[2022年03月08日] 掲載	March 8, 2022, 1:51 p.m.