Mutt before 2.0.2 and NeoMutt before 2020-11-20 did not ensure that $ssl_force_tls was processed if an IMAP servers initial server response was invalid. The connection was not properly closed, and the code could continue attempting to authenticate. This could result in authentication credentials being exposed on an unencrypted connection, or to a machine-in-the-middle.
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Mutt | Mutt | * | 2.0.2 (excluding) |
| Neomutt | Neomutt | * | 2020-11-20 (excluding) |
| Red Hat Enterprise Linux 8 | RedHat | mutt-5:2.0.7-1.el8 | * |
| Mutt | Ubuntu | bionic | * |
| Mutt | Ubuntu | focal | * |
| Mutt | Ubuntu | groovy | * |
| Mutt | Ubuntu | trusty | * |
| Mutt | Ubuntu | upstream | * |
| Mutt | Ubuntu | xenial | * |
| Neomutt | Ubuntu | bionic | * |
| Neomutt | Ubuntu | groovy | * |
| Neomutt | Ubuntu | trusty | * |
| Neomutt | Ubuntu | upstream | * |