Description
The kdb_ldap plugin in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) 1.9 through 1.9.1, when the LDAP back end is used, allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via a kinit operation with incorrect string case for the realm, related to the is_principal_in_realm, krb5_set_error_message, krb5_ldap_get_principal, and process_as_req functions.
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 | krb5 | 1.10+dfsg~alpha1-1 | — |
| Debian 13 | krb5 | 1.10+dfsg~alpha1-1 | — |
| Debian 12 | krb5 | 1.10+dfsg~alpha1-1 | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 6 | krb5 +6 | 1.9-9.el6_1.2 | RHSA-2011:1379 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | krb5 | 1.15-1.1 | openSUSE-SU-2024:10004-1 |
Advisories 2
- openSUSE-SU-2024:10004-1 krb5-1.15-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- RHSA-2011:1379 Red Hat Security Advisory: krb5 security update Red Hat Security Advisories (RHSA) · Jan 29, 2026
References
- http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=629558
- MDVSA-2011:159 vendor-advisory
- VU#659251 third-party-advisory
- http://web.mit.edu/kerberos/advisories/MITKRB5-SA-2011-006.txt
- RHSA-2011:1379 vendor-advisory