qpopper 4.01 with PAM based authentication on Red Hat systems generates different error messages when an invalid username is provided instead of a valid name, which allows remote attackers to determine valid usernames on the system.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Qpopper | Qualcomm | 4.0.1 (including) | 4.0.1 (including) |