Description
The lookup_lockout_policy function in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) 1.8 through 1.8.4 and 1.9 through 1.9.1, when the db2 (aka Berkeley DB) or LDAP back end is used, allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via vectors that trigger certain process_as_req errors.
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 | — |
| Debian 6.0 | krb5 | 1.8.3+dfsg-4squeeze5 | DSA-2379-1 |
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 3
- DSA-2379-1 krb5 - several Debian Security (DSA / DLA) · Mar 9, 2026
- 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
- MDVSA-2011:159 vendor-advisory
- MDVSA-2011:160 vendor-advisory
- openSUSE-SU-2011:1169 vendor-advisory
- VU#659251 third-party-advisory
- http://web.mit.edu/kerberos/advisories/MITKRB5-SA-2011-006.txt
- RHSA-2011:1379 vendor-advisory