Description
Version 4 of the Kerberos protocol (krb4), as used in Heimdal and other packages, allows an attacker to impersonate any principal in a realm via a chosen-plaintext attack.
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 | heimdal | 0.5.2-1 | — |
| Debian 14 | krb5 | 1.2.7-3 | — |
| Debian 13 | heimdal | 0.5.2-1 | — |
| Debian 13 | krb5 | 1.2.7-3 | — |
| Debian 12 | heimdal | 0.5.2-1 | — |
| Debian 12 | krb5 | 1.2.7-3 | — |
| Debian 3.0 | heimdal | 0.4e-7.woody.8 | DSA-269 |
| Debian 3.0 | krb4 | 1.1-8-2.3 | DSA-273 |
| Debian 3.0 | krb5 | 1.2.4-5woody4 | DSA-266 |
Advisories 3
- DSA-273 krb4 - Cryptographic weakness Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-266 krb5 - several vulnerabilities Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-269 heimdal - Cryptographic weakness Debian Security (DSA / DLA) · Mar 9, 2026
References
- DSA-269 vendor-advisory
- RHSA-2003:052 vendor-advisory
- 20030331 GLSA: krb5 & mit-krb5 (200303-28) mailing-list
- http://web.mit.edu/kerberos/www/advisories/MITKRB5-SA-2003-004-krb4.txt
- oval:org.mitre.oval:def:248 vdb-entry signature
- RHSA-2003:091 vendor-advisory
- DSA-273 vendor-advisory
- RHSA-2003:051 vendor-advisory
- VU#623217 third-party-advisory
- DSA-266 vendor-advisory
- 20030317 MITKRB5-SA-2003-004: Cryptographic weaknesses in Kerberos v4 protocol mailing-list
- 7113 vdb-entry