| Name | CVE-2025-3576 |
| Description | A vulnerability in the MIT Kerberos implementation allows GSSAPI-protected messages using RC4-HMAC-MD5 to be spoofed due to weaknesses in the MD5 checksum design. If RC4 is preferred over stronger encryption types, an attacker could exploit MD5 collisions to forge message integrity codes. This may lead to unauthorized message tampering. |
| Source | CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| Debian Bugs | 1103525 |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|
| krb5 (PTS) | bullseye | 1.18.3-6+deb11u5 | vulnerable |
| bullseye (security) | 1.18.3-6+deb11u6 | vulnerable |
| bookworm, bookworm (security) | 1.20.1-2+deb12u2 | vulnerable |
| sid, trixie | 1.21.3-5 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|
| krb5 | source | (unstable) | 1.21.2-1 | | | 1103525 |
Notes
[bookworm] - krb5 <no-dsa> (Minor issue)
https://bugzilla.redhat.com/show_bug.cgi?id=2359465
CVE relates to issues covered in:
https://i.blackhat.com/EU-22/Thursday-Briefings/EU-22-Tervoort-Breaking-Kerberos-RC4-Cipher-and-Spoofing-Windows-PACs-wp.pdf
Since upstream 1.21 (cf. https://web.mit.edu/kerberos/krb5-1.21/) the KDC
will no longer issue tickets with RC4 or triple-DES session keys unless
explicitly configured with the new allow_rc4 or allow_des3 variables respectively.
https://github.com/krb5/krb5/commit/1b57a4d134bbd0e7c52d5885a92eccc815726463
https://github.com/krb5/krb5/commit/2cbd847e0e92bc4e219b65c770ae33f851b22afc