In OpenLDAP through 2.4.57 and 2.5.x through 2.5.1alpha, an assertion failure in slapd…
Priority HIGH 69CWE-617Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Will not fix Red Hat: no fix planned
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-617.
Summary
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.
Why it matters now
EPSS 0.66114 99th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Will not fix Red Hat: no fix planned
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 5
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:openldap:openldap:*:*:*:*:*:*:*:* | up to 2.4.57 | Vulnerable | openldap |
| cpe:2.3:a:openldap:openldap:2.5.0:alpha:*:*:*:*:*:* | 2.5.0 alpha | Vulnerable | openldap |
| cpe:2.3:a:openldap:openldap:2.5.1:alpha:*:*:*:*:*:* | 2.5.1 alpha | Vulnerable | openldap |
| cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* | 9.0 | Vulnerable | Debian |
| cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* | 10.0 | Vulnerable | Debian |
- cpe:2.3:a:openldap:openldap:*:*:*:*:*:*:*:* Versions up to 2.4.57 Vulnerable ·openldap
- cpe:2.3:a:openldap:openldap:2.5.0:alpha:*:*:*:*:*:* Versions 2.5.0 alpha Vulnerable ·openldap
- cpe:2.3:a:openldap:openldap:2.5.1:alpha:*:*:*:*:*:* Versions 2.5.1 alpha Vulnerable ·openldap
- cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Debian
- cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* Versions 10.0 Vulnerable ·Debian
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Will not fix |
Not affected: 2 products
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2021-27212
- 2026-10-03 Alias added: GHSA-274h-c788-hf3c
References
Patch 2
Advisory 3
Other 2
- [bookkeeper-issues] 20210628 [GitHub] [bookkeeper] padma81 opened a new issue #2746: Security Vulnerabilities in CentOS 7 image, Upgrade image to CentOS 8
- [bookkeeper-issues] 20210629 [GitHub] [bookkeeper] padma81 opened a new issue #2746: Security Vulnerabilities in CentOS 7 image, Upgrade image to CentOS 8
Sources
- CVE-2021-27212 · CVE Program
- CVE-2021-27212 · NVD
- FIRST EPSS
- GHSA-274h-c788-hf3c · GitHub Advisory Database · CC BY 4.0
- CVE-2021-27212 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences