Denial of service in OpenLDAP

Published: 2021-02-17 | Updated: 2021-03-23
Risk Medium
Patch available YES
Number of vulnerabilities 1
CVE-ID CVE-2021-27212
Exploitation vector Network
Public exploit N/A
Vulnerable software
Server applications / Directory software, identity management


Security Bulletin

This security bulletin contains information about 1 vulnerabilities.

Updated: 23.03.2021

Changed bulletin status to patched.

1) Reachable Assertion

EUVDB-ID: #VU50779

Risk: Medium


CVE-ID: CVE-2021-27212

CWE-ID: CWE-617 - Reachable Assertion

Exploit availability: No


The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a reachable assertion when processing LDAP packets within the issuerAndThisUpdateCheck() function in  schema_init.c. A remote attacker can send a specially crafted packet with a short timestamp to the slapd and perform a denial of service (DoS) attack.


Install update from vendor's website.

Vulnerable software versions

OpenLDAP: 2.4 - 2.4.57

CPE2.3 External links

Q & A

Can this vulnerability be exploited remotely?

How the attacker can exploit this vulnerability?

Is there known malware, which exploits this vulnerability?