SPIP < 4.4.18 Code Injection via Navigation Endpoint on SQLite

SPIP before 4.4.18 contains a code injection vulnerability in SQLite-backed installations. The navigation menu endpoint improperly handles array-typed user input, which bypasses input sanitization and allows the value to break out of an internal quoted string context when evaluated as PHP. An authenticated attacker with at minimum editor (redacteur) privileges can submit a single crafted GET request to /ecrire/?exec=navigation to execute arbitrary OS commands in the web server process. MySQL-backed installations are not affected.