CVE-2021-27212

Name: CVE-2021-27212
Creator: NVD / NIST
Published: 2021-02-14T03:15:12.957+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 64.15%

Last modified Jun 17, 2026

CVE-2021-27212 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. 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.. EPSS estimates a 64.15% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

64.15%

99.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-617

Affected Software

Vendor	Product	Versions	Update
Openldap	Openldap	<= 2.4.57	—
Openldap	Openldap	2.5.0	Alpha
Openldap	Openldap	2.5.1	Alpha
Debian	Debian Linux	9.0	—
Debian	Debian Linux	10.0	—

References

https://bugs.openldap.org/show_bug.cgi?id=9454Exploit, Issue Tracking, Vendor Advisory
https://git.openldap.org/openldap/openldap/-/commit/3539fc33212b528c56b716584f2c2994af7c30b0Patch, Vendor Advisory
https://git.openldap.org/openldap/openldap/-/commit/9badb73425a67768c09bcaed1a9c26c684af6c30Patch, Vendor Advisory
https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.apache.org%3E
https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.apache.org%3E
https://lists.debian.org/debian-lts-announce/2021/02/msg00035.htmlMailing List, Third Party Advisory
https://security.netapp.com/advisory/ntap-20210319-0005/Third Party Advisory
https://www.debian.org/security/2021/dsa-4860Third Party Advisory
https://bugs.openldap.org/show_bug.cgi?id=9454Exploit, Issue Tracking, Vendor Advisory
https://git.openldap.org/openldap/openldap/-/commit/3539fc33212b528c56b716584f2c2994af7c30b0Patch, Vendor Advisory
https://git.openldap.org/openldap/openldap/-/commit/9badb73425a67768c09bcaed1a9c26c684af6c30Patch, Vendor Advisory
https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.apache.org%3E
https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.apache.org%3E
https://lists.debian.org/debian-lts-announce/2021/02/msg00035.htmlMailing List, Third Party Advisory
https://security.netapp.com/advisory/ntap-20210319-0005/Third Party Advisory
https://www.debian.org/security/2021/dsa-4860Third Party Advisory

Timeline

Published: Feb 14, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-27212?

How severe is CVE-2021-27212?

CVE-2021-27212 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 64.15% probability of exploitation in the next 30 days.

How do I fix CVE-2021-27212?

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-2021-27212?

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

Scan your code now

Source: NVD / NIST