2.5

CVE-2021-27645: debian debian_linux Double Free

Modified
AliasesMGASA-2021-0138UBUNTU-CVE-2021-27645DEBIAN-CVE-2021-27645
Published 24-02-2021Last modified 14-10-2026

Vulnerability summary

CVE-2021-27645 is a low (CVSS 2.5) Double Free vulnerability in debian debian_linux. EPSS estimates a 0.39% chance of exploitation in the next 30 days, higher than 32.6% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 2.5, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
2.5/10
010
Low · v3.1 (CVE.org)
EPSS score
0.39%
0%100%
Low · +0.01 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 5 · Related 2
DLA-3152-1MGASA-2021-0150OPENSUSE-SU-2024:10792-1RHSA-2021:4358USN-5310-1

Timeline

  1. 24-02-2021
    PublishedVulnerability first disclosed.
  2. 14-10-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.39%

Chance of exploitation in the next 30 days

Percentile

33%

Versus all other CVEs

30-day change

Increase +0.01 pp

From 0.37% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Debian2 products
Fedoraproject1 product
Gnu1 product
Mageia1 product
  • glibc< 2.32-15.mga8
Ubuntu1 product
  • glibc< 2.31-0ubuntu9.7

5 vendors · 6 products

References

13 links
Show all 13 references