7.5

CVE-2021-27212: debian debian_linux Reachable Assertion

CVSS: 7.5v3.1HighModified
AliasesALPINE-CVE-2021-27212UBUNTU-CVE-2021-27212USN-4744-1
Published 14-02-2021Last modified 14-10-2026
Open JSON

Vulnerability summary

CVE-2021-27212 is a high (CVSS 7.5) Reachable Assertion vulnerability in debian debian_linux. EPSS estimates a 66.11% chance of exploitation in the next 30 days, higher than 99.2% of scored vulnerabilities. 1 public exploit is recorded.

Overall risk
53/100
0100
High · default modelHow is this calculated?
CVSS score
7.5/10
010
High · v3.1 (NVD)
EPSS score
66.11%
0%100%
Critical · +1.97 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1reference

Advisory lineage

Upstream 0 · Downstream 7 · Related 6
MGASA-2021-0105OPENSUSE-SU-2021:0408-1SUSE-SU-2021:0692-1SUSE-SU-2021:0693-1SUSE-SU-2021:0723-1SUSE-SU-2021:14700-1

Timeline

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

Description

In OpenLDAP through 2.4.57 and 2.5.x through 2.5.1alpha, an assertion failure in slapd can occur in the issuerAndThisUpdateCheck function via a crafted packet, resulting in a denial of service (daemon exit) via a short timestamp. This is related to schema_init.c and checkTime.

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

66.11%

Chance of exploitation in the next 30 days

Percentile

99%

Versus all other CVEs

30-day change

+1.97 pp

From 64.15% on 19-09-2026

19-09-202619-10-2026
EPSS score
66.11%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

1 found
  • referenceUnverified

    Exploit Reference (bugs.openldap.org)

    Maturity: unknown

Weaknesses

CWE · root cause

Affected systems

Debian2 products
  • openldap< 2.4.47+dfsg-3+deb10u6 | < 2.4.44+dfsg-5+deb9u8 | < 2.4.57+dfsg-2
  • debian_linuxEOL9.0 | 10.0
Alpine1 product
  • openldap< 2.4.50-r2 | < 2.4.57-r1
Openldap1 product
  • openldap≤ 2.4.57 | 2.5.0:alpha | 2.5.1:alpha
Ubuntu1 product
  • openldap< 2.4.31-1+nmu2ubuntu8.5+esm8 | < 2.4.42+dfsg-2ubuntu3.13 | < 2.4.45+dfsg-1ubuntu1.10 | < 2.4.49+dfsg-2ubuntu1.7

4 vendors · 5 products

References

16 links
Show all 16 references