A malicious or compromised Flatpak repository can write attacker-controlled content to arbitrary locations on the host filesystem via extract_extra_da...

A malicious or compromised Flatpak repository can write attacker-controlled content to arbitrary locations on the host filesystem via extract_extra_data(). On system installs, the write happens as root. Two issues combine: files/extra is resolved via path operations that follow symlinks, and blob names from xa.extra-data-sources are not sanitized against .. traversal.