Description
modrdn.c in slapd in OpenLDAP 2.4.x before 2.4.24 allows remote attackers to cause a denial of service (daemon crash) via a relative Distinguished Name (DN) modification request (aka MODRDN operation) that contains an empty value for the OldDN field.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | openldap | 2.4.25-1 | — |
| Debian 13 | openldap | 2.4.25-1 | — |
| Debian 12 | openldap | 2.4.25-1 | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 6 | compat-openldap | 2.4.19_2.3.43-15.el6_0.2 | RHSA-2011:0347 |
| RHEL 6 | openldap +4 | 2.4.19-15.el6_0.2 | RHSA-2011:0347 |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
Exploit-DB 1
- OpenLDAP 2.4.x - 'modrdn' NULL OldDN Remote Denial of Service EDB-35445 · dos · Jan 3, 2011 · verified
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 1
- RHSA-2011:0347 Red Hat Security Advisory: openldap security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
References
- GLSA-201406-36 vendor-advisory
- openldap-modrdnc-dos(66239) vdb-entry
- [oss-security] 20110301 Re: CVE Request -- OpenLDAP -- two issues mailing-list
- [oss-security] 20110301 Re: CVE Request -- OpenLDAP -- two issues mailing-list
- http://www.openldap.org/its/index.cgi/Software%20Bugs?id=6768
- [openldap-announce] 20110212 OpenLDAP 2.4.24 available mailing-list
- MDVSA-2011:056 vendor-advisory
- https://bugzilla.novell.com/show_bug.cgi?id=674985
- RHSA-2011:0347 vendor-advisory
- [oss-security] 20110228 Re: CVE Request -- OpenLDAP -- two issues mailing-list
- http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10705
- MDVSA-2011:055 vendor-advisory
- [oss-security] 20110228 Re: CVE Request -- OpenLDAP -- two issues mailing-list
- 43718 third-party-advisory
- USN-1100-1 vendor-advisory
- 1025191 vdb-entry
- ADV-2011-0665 vdb-entry
- 43331 third-party-advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=680975
- http://www.openldap.org/devel/cvsweb.cgi/servers/slapd/modrdn.c.diff?r1=1.170.2.8&r2=1.170.2.9