CVE-2020-11879

An issue was discovered in GNOME Evolution before 3.35.91. By using the proprietary (non-RFC6068) “mailto?attach=…” parameter, a website (or other source of mailto links) can make Evolution attach local files or directories to a composed email message without showing a warning to the user, as demonstrated by an attach=. value.

Mitigation

Either:
1. Do not use mailto links at all
2. Always double-check in the user interface that there are no unwanted attachments before sending emails; especially when the email originates from clicking a mailto link.