Kerberos 4 key servers allow a user to masquerade as another by breaking and generating session keys.
| Name | Vendor | Start Version | End Version | 
|---|---|---|---|
| Kerberos | Mit | 4.0 (including) | 4.0 (including) | 
| Kerberos_5 | Mit | - (including) | - (including) | 
| Multinet | Process_software | 3.4 (including) | 3.4 (including) | 
| Multinet | Process_software | 3.5 (including) | 3.5 (including) |