Cryptomator for IOS offers multi-platform transparent client-side encryption for files in the cloud. Prior to version 2.8.3, an integrity check vulnerability allows an attacker tamper with the vault configuration file leading to a man-in-the-middle vulnerability in Hub key loading mechanism. Before this fix, the client trusted endpoints from the vault config without host authenticity checks, which could allow token exfiltration by mixing a legitimate auth endpoint with a malicious API endpoint.

Impacted are users unlocking Hub-backed vaults with affected client versions in environments where an attacker can alter the vault.cryptomator file. This issue has been patched in version 2.8.3.