The PDOSessionHandler classallows to store sessions on a PDO connection. Under some configurations (see below)andwith a well-crafted payload, it was possible to do a denial of service on a Symfony application without too much resources.
An application is vulnerable when:- It is using PDOSessionHandler to store its sessions;- And it uses MySQL as a backend for sessions managed by PDOSessionHandler;- And the SQL mode does not contain STRICT_ALL_TABLES or STRICT_TRANS_TABLES (check via SELECT @@sql_mode).
POC:
https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/44768.tgz