|Affected Products:||Canary Mail for iOS and MacOS versions 3.20 and 3.21, MailCore2 library version 0.6.4|
|Class:||Improper Certificate Validation (CWE-295)|
|Discovered by:||Rayd Debbas|
CENSUS identified that the Canary Mail software in versions 3.20 and 3.21 (and possibly previous versions) is missing a certificate validation check when performing an IMAP connection configured with STARTTLS. This vulnerability allows man-in-the-middle attackers to collect a victim user's email credentials (while these are communicated to the IMAP service), to access email messages and perform other IMAP actions to the victim account, but also to modify email messages while in-transit to Canary Mail. CENSUS strongly recommends to iOS and MacOS users of the Canary Mail software to update to version 3.22, as this version carries a fix for the aforementioned vulnerability. The same vulnerability also affects other software that are based on the MailCore2 library (including version 0.6.4). A patch for the library is publicly available, however this has not been incorporated yet into an official library release.
The recent key reinstallation attacks (KRACK) against the WPA2 protocol revealed how an adversary can easily eavesdrop, and in some cases
tamper, a Wi-Fi connection secured by the WPA2 protocol. At the same
time, Wi-Fi automatic association attacks achieve a similar result
(man-in-the-middle position) not by attacking the WPA2 protocol directly
but by enforcing Wi-Fi clients to join a rogue Access Point.