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.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Kerberos | Mit | 4 (including) | 4 (including) |
| Red Hat Enterprise Linux AS (Advanced Server) version 2.1 | RedHat | * | |
| Red Hat Enterprise Linux ES version 2.1 | RedHat | * | |
| Red Hat Enterprise Linux WS version 2.1 | RedHat | * | |
| Red Hat Linux 6.2 | RedHat | * | |
| Red Hat Linux 7.0 | RedHat | * | |
| Red Hat Linux 7.1 | RedHat | * | |
| Red Hat Linux 7.1 | RedHat | * | |
| Red Hat Linux 7.2 | RedHat | * | |
| Red Hat Linux 7.3 | RedHat | * | |
| Red Hat Linux 8.0 | RedHat | * | |
| Red Hat Linux 9 | RedHat | * | |
| Red Hat Linux Advanced Workstation 2.1 | RedHat | * |