CVE-2021-27212
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.
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 66.1%, higher than 99% of all known CVEs. Patch or mitigate before the next change window.
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 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 66.11% probability · 99th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-617
- Affected
- openldap/openldap · debian/debian linux
- Source
- cve@mitre.org
EPSS moved from 66.1% on 15 October 2026 to 66.1% on 3 November 2026. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”.
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
- https://cert-portal.siemens.com/productcert/html/ssa-398330.html
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.