mod_usertrack in Apache 1.3.11 through 1.3.20 generates session IDs using predictable information including host IP address, system time and server process ID, which allows local users to obtain session IDs and bypass authentication when these session IDs are used for authentication.
Authenticating a user, or otherwise establishing a new user session, without invalidating any existing session identifier gives an attacker the opportunity to steal authenticated sessions.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Http_server | Apache | 1.3.11 (including) | 1.3.20 (including) |
Such a scenario is commonly observed when: