roundcube version 1.3.4 and earlier contains an Insecure Permissions vulnerability in enigma plugin that can result in exfiltration of gpg private key. This attack appear to be exploitable via network connectivity.

Roundcube Webmail before 1.1.10, 1.2.x before 1.2.7, and 1.3.x before 1.3.3 allows unauthorized access to arbitrary files on the host's filesystem, including configuration files, as exploited in the wild in November 2017. The attacker must be able to authenticate at the target system with a valid username/password as the attack requires an active session. The issue is related to file-based attachment plugins and _task=settings&_action=upload-display&_from=timezone requests.