Is CVE-2021-33910 in the CISA KEV catalog?

No. CVE-2021-33910 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-33910?

CVE-2021-33910 has a CVSS v3 base score of 5.5 (MEDIUM).

What is the EPSS score for CVE-2021-33910?

CVE-2021-33910 has an EPSS score of 8.65% (94th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-33910?

Upgrade systemd on debian 11 to 247.3-6 or later. Fixes are available for 2 affected products.

CVE & CISA-KEV Catalog

CVE-2021-33910

MEDIUMEPSS 94th pctl

5.5

CVSS v3

NVD

Description

basic/unit-name.c in systemd prior to 246.15, 247.8, 248.5, and 249.1 has a Memory Allocation with an Excessive Size Value (involving strdupa and alloca for a pathname controlled by a local attacker) that results in an operating system crash.

CWE-770Allocation of Resources Without Limits or Throttling

How to fix

Remediation Available

systemdDebian

Fixed in:247.3-6CVE-2021-33910

systemdUbuntu

Fixed in:229-4ubuntu21.31+esm1USN-5013-2

Fixed in:237-3ubuntu10.49USN-5013-1

Fixed in:245.4-4ubuntu3.10USN-5013-1

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 VectorLocal

Attack ComplexityLow

Privileges RequiredLow

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

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

Exploit Intelligence

8.65%probability of exploitation in 30 days

94thpercentile

High risk: more likely to be exploited than 94% of all known CVEs.

References

Patch9

Exploit2

Third-Party Advisory3

Other references3

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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 2025-06-09.