Description
The kdc_handle_protected_negotiation function in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) 1.8.x, 1.9.x before 1.9.5, and 1.10.x before 1.10.3 attempts to calculate a checksum before verifying that the key type is appropriate for a checksum, which allows remote attackers to execute arbitrary code or cause a denial of service (uninitialized pointer free, heap memory corruption, and daemon crash) via a crafted AS-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-2 | — |
| Debian 13 | krb5 | 1.10.1+dfsg-2 | — |
| Debian 12 | krb5 | 1.10.1+dfsg-2 | — |
| Debian 6.0 | krb5 | 1.8.3+dfsg-4squeeze6 | DSA-2518-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 6 | krb5 +6 | 1.9-33.el6_3.2 | RHSA-2012:1131 |
Advisories 2
- RHSA-2012:1131 Red Hat Security Advisory: krb5 security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- DSA-2518-1 krb5 - denial of service Debian Security (DSA / DLA) · Mar 9, 2026
References
- http://web.mit.edu/kerberos/advisories/MITKRB5-SA-2012-001.txt
- RHSA-2012:1131 vendor-advisory
- openSUSE-SU-2012:0967 vendor-advisory
- DSA-2518 vendor-advisory
- MDVSA-2012:120 vendor-advisory