CVE-2021-27645

Name: CVE-2021-27645
Creator: NVD / NIST
Published: 2021-02-24T15:15:13.837+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

LOWCVSS 2.5/10EPSS 0.37%

Last modified Jun 17, 2026

CVE-2021-27645 is a low-severity vulnerability rated 2.5/10 on the CVSS scale. The nameserver caching daemon (nscd) in the GNU C Library (aka glibc or libc6) 2.29 through 2.33, when processing a request for netgroup lookup, may crash due to a double-free, potentially resulting in degraded service or Denial of Service on the local system. This is related to netgroupcache.c.. EPSS estimates a 0.37% chance of exploitation in the next 30 days.

Description

The nameserver caching daemon (nscd) in the GNU C Library (aka glibc or libc6) 2.29 through 2.33, when processing a request for netgroup lookup, may crash due to a double-free, potentially resulting in degraded service or Denial of Service on the local system. This is related to netgroupcache.c.

Metrics

CVSS 3.1

2.5/10

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

EPSS Probability

0.37%

29.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Gnu	Glibc	>= 2.29, <= 2.33
Fedoraproject	Fedora	33
Fedoraproject	Fedora	34
Debian	Debian Linux	10.0

References

https://lists.debian.org/debian-lts-announce/2022/10/msg00021.htmlMailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7LZNT6KTMCCWPWXEOGSHD3YLYZKUGMH5/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I7TS26LIZSOBLGJEZMJX4PXT5BQDE2WS/
https://security.gentoo.org/glsa/202107-07Third Party Advisory
https://sourceware.org/bugzilla/show_bug.cgi?id=27462Issue Tracking, Patch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2022/10/msg00021.htmlMailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7LZNT6KTMCCWPWXEOGSHD3YLYZKUGMH5/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I7TS26LIZSOBLGJEZMJX4PXT5BQDE2WS/
https://security.gentoo.org/glsa/202107-07Third Party Advisory
https://sourceware.org/bugzilla/show_bug.cgi?id=27462Issue Tracking, Patch, Third Party Advisory

Timeline

Published: Feb 24, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-27645?

How severe is CVE-2021-27645?

CVE-2021-27645 has a CVSS score of 2.5/10 (LOW severity). The EPSS model estimates a 0.37% probability of exploitation in the next 30 days.

How do I fix CVE-2021-27645?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-27645?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST