Is CVE-2021-34557 in the CISA KEV catalog?

No. CVE-2021-34557 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-34557?

CVE-2021-34557 has a CVSS v3 base score of 4.6 (MEDIUM).

What is the EPSS score for CVE-2021-34557?

CVE-2021-34557 has an EPSS score of 0.48% (38th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-34557?

Upgrade xscreensaver on debian 11 to 5.45+dfsg1-2 or later.

CVE & CISA-KEV Catalog

CVE-2021-34557

MEDIUM

4.6

CVSS v3

NVD

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.

CWE-120Classic Buffer Overflow

How to fix

Remediation Available

xscreensaverDebian

Fixed in:5.45+dfsg1-2CVE-2021-34557

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorPhysical

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploit Intelligence

0.48%probability of exploitation in 30 days

38thpercentile

Low risk: more likely to be exploited than 38% of all known CVEs.

References

Patch1

github.com

Exploit3

Third-Party Advisory2

Other references1

lists.fedoraproject.org

Related Vulnerabilities

Other CWE-120 (Classic Buffer Overflow) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2014-0195	Medium	6.8	100%	-	Fix
CVE-2017-7269	Critical	9.8	100%	KEV	-
CVE-2019-11043	High	8.7	99%	KEV + Ransom	Fix
CVE-2011-4862	High	10.0	95%	-	Fix
CVE-2007-5659	High	7.8	94%	KEV	Fix
CVE-2022-3786	High	7.5	91%	-	Fix

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.