Description
The unparse implementation in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) 1.6.x through 1.9, when an LDAP backend is used, allows remote attackers to cause a denial of service (file descriptor exhaustion and daemon hang) via a principal name that triggers use of a backslash escape sequence, as demonstrated by a \n sequence.
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 | 1.8.3+dfsg-5 | — |
| Debian 13 | krb5 | 1.8.3+dfsg-5 | — |
| Debian 12 | krb5 | 1.8.3+dfsg-5 | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 6 | krb5 +6 | 1.8.2-3.el6_0.4 | RHSA-2011:0200 |
| RHEL 5 | krb5 +5 | 1.6.1-55.el5_6.1 | RHSA-2011:0199 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | krb5 | 1.15-1.1 | openSUSE-SU-2024:10004-1 |
Advisories 3
- RHSA-2011:0200 Red Hat Security Advisory: krb5 security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- openSUSE-SU-2024:10004-1 krb5-1.15-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- RHSA-2011:0199 Red Hat Security Advisory: krb5 security update Red Hat Security Advisories (RHSA) · Jan 29, 2026
References
- MDVSA-2011:025 vendor-advisory
- 46265 vdb-entry
- 20111013 VMSA-2011-0012 VMware ESXi and ESX updates to third party libraries and ESX Service Console mailing-list
- 46397 third-party-advisory
- ADV-2011-0347 vdb-entry
- 43260 third-party-advisory
- ADV-2011-0333 vdb-entry
- RHSA-2011:0199 vendor-advisory
- 43273 third-party-advisory
- http://web.mit.edu/kerberos/advisories/MITKRB5-SA-2011-002.txt
- 20110208 MITKRB5-SA-2011-002 KDC denial of service attacks [CVE-2011-0281 CVE-2011-0282 CVE-2011-0283] mailing-list
- 1025037 vdb-entry
- SUSE-SR:2011:004 vendor-advisory
- http://www.vmware.com/security/advisories/VMSA-2011-0012.html
- MDVSA-2011:024 vendor-advisory
- ADV-2011-0464 vdb-entry
- 8073 third-party-advisory
- kerberos-ldap-descriptor-dos(65324) vdb-entry
- ADV-2011-0330 vdb-entry
- [kerberos] 20101222 LDAP handle unavailable: Can't contact LDAP server mailing-list
- 43275 third-party-advisory
- RHSA-2011:0200 vendor-advisory