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01 Record

CVE-2021-27645

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

LowPUBLISHEDCNA: mitre
CNA base score2.5 CVSS v3.xCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L

02 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

03 Exploitation and scoring

Exploitation
Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
SSVC decision
  • ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
  • AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
  • Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.
EPSS probability
0.38% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 32.3% of scored records. A rank, not a probability.
NVD base score
2.5 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L
NVD analysis status
Modified. NVD last modified this record on 2026-10-14.
Red Hat severity
Low. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published
2021-02-24 00:00Z5 YR AGO
Last updated
2026-10-14 11:39Z15 DAYS AGO
Reserved
2021-02-24
Assigning CNA
mitre
Record state
PUBLISHED
Severity
Low (CVSS 2.5)
CNA CVSS vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L
Weaknesses
Data version
5.2
Document digest
60b4c99fca6a567edc4a120fc0fb1fa89fe809dbfc1ff077e960f26db27ea4d2

05 Affected products

VendorProductVersionsPlatforms
debiandebian_linuxNot specified—
fedoraprojectfedoraNot specified—
gnuglibcNot specified—
redhatenterprise_linuxNot specified—

06 References

07 Fixed in

AlmaLinux 8

  • compat-libpthread-nonshared
    Fixed in 2.28-164.el8
  • glibc-benchtests
    Fixed in 2.28-164.el8
  • glibc-nss-devel
    Fixed in 2.28-164.el8
  • glibc-static
    Fixed in 2.28-164.el8
  • glibc-utils
    Fixed in 2.28-164.el8
  • nss_hesiod
    Fixed in 2.28-164.el8

Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

Arch Linux

  • glibc
    Fixed in 2.34-1

Source: Arch Linux Security Tracker, the Arch Linux security team. Reformatted by exploit.cc.

CloudLinux 8

  • compat-libpthread-nonshared
    Fixed in 2.28-164.el8
  • glibc-benchtests
    Fixed in 2.28-164.el8
  • glibc-nss-devel
    Fixed in 2.28-164.el8
  • glibc-static
    Fixed in 2.28-164.el8
  • glibc-utils
    Fixed in 2.28-164.el8
  • nss_hesiod
    Fixed in 2.28-164.el8

Derived from AlmaLinux 8. Partial coverage: only packages taken from AlmaLinux 8 are listed.

Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

Debian 12

  • glibc
    Fixed in 2.31-10

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 13

  • glibc
    Fixed in 2.31-10

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 14

  • glibc
    Fixed in 2.31-10

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 20.04 LTS

  • glibc
    Fixed in 2.31-0ubuntu9.7

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.