vaultwarden is an unofficial Bitwarden compatible server written in Rust, formerly known as bitwarden_rs. Attacker with authenticated access to the vaultwarden admin panel can execute arbitrary code in the system. The attacker could then change some settings to use sendmail as mail agent but adjust the settings in such a way that it would use a shell command. It then also needed to craft a special favicon image which would have the commands embedded to run during for example sending a test email. This vulnerability is fixed in 1.33.0.
The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.