Description
The prep_reprocess_req function in do_tgs_req.c in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) before 1.10.5 does not properly perform service-principal realm referral, which allows remote authenticated users to cause a denial of service (NULL pointer dereference and daemon crash) via a crafted TGS-REQ request.
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 | 1.10.1+dfsg-5 | — |
| Debian 13 | krb5 | 1.10.1+dfsg-5 | — |
| Debian 12 | krb5 | 1.10.1+dfsg-5 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 14.04 LTS | krb5 | 1.12+dfsg-2ubuntu4.2 | USN-2310-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 6 | krb5 +6 | 1.10.3-10.el6_4.2 | RHSA-2013:0748 |
Advisories 2
- RHSA-2013:0748 Red Hat Security Advisory: krb5 security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- USN-2310-1 krb5 vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
References
- MDVSA-2013:157 vendor-advisory
- openSUSE-SU-2013:0904 vendor-advisory
- MDVSA-2013:158 vendor-advisory
- FEDORA-2013-5286 vendor-advisory
- openSUSE-SU-2013:0967 vendor-advisory
- openSUSE-SU-2013:0746 vendor-advisory
- FEDORA-2013-5280 vendor-advisory
- https://github.com/krb5/krb5/commit/8ee70ec63931d1e38567905387ab9b1d45734d81
- http://krbdev.mit.edu/rt/Ticket/Display.html?id=7600
- RHSA-2013:0748 vendor-advisory