The SMTP client in Mozilla Thunderbird 1.0.5 BETA, 1.0.7, and possibly other versions, does not notify users when it cannot establish a secure channel with the server, which allows remote attackers to obtain authentication information without detection via a man-in-the-middle (MITM) attack that bypasses TLS authentication or downgrades CRAM-MD5 authentication to plain authentication.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Thunderbird | Mozilla | 1.0.5-beta (including) | 1.0.5-beta (including) |
| Thunderbird | Mozilla | 1.0.7 (including) | 1.0.7 (including) |
| Mozilla-thunderbird | Ubuntu | dapper | * |
| Mozilla-thunderbird | Ubuntu | devel | * |
| Mozilla-thunderbird | Ubuntu | edgy | * |
| Mozilla-thunderbird | Ubuntu | feisty | * |