offlineimap before 6.3.2 does not check for SSL server certificate validation when "ssl = yes" option is specified which can allow man-in-the-middle attacks.
| Software | From | Fixed in |
|---|---|---|
| debian / debian_linux | 8.0 | 8.0.x |
| debian / debian_linux | 9.0 | 9.0.x |
| debian / debian_linux | 10.0 | 10.0.x |
| offlineimap / offlineimap | - | 6.3.2 |