Kerberos 4 key servers allow a user to masquerade as another by breaking and generating session keys.
| Software | From | Fixed in |
|---|---|---|
| process_software / multinet | 3.4 | 3.4.x |
| mit / kerberos | 4.0 | 4.0.x |
| process_software / multinet | 3.5 | 3.5.x |
| sun / sunos | 5.3 | 5.3.x |
| sun / sunos | 5.4 | 5.4.x |