GHSA-3w55-933p-8pv5: Strands Agents: Local Privilege Escalation via Symlink Attack in Default Session File Storage

The FileSessionManager defaults to storing session data in /tmp/strands/sessions/ (a world-writable directory) using predictable file paths and a write pattern (open(path + ".tmp", "w") → os.replace()) that follows symbolic links. A local attacker can exploit this to overwrite arbitrary files or inject malicious session data for persistent prompt injection.