The strands-agents FileSessionManager stores session data in a world-writable directory (/tmp/strands/sessions/) using predictable file paths and writes that follow symbolic links. This allows a local attacker to create symlinks to arbitrary files, causing the application to overwrite those files with attacker-controlled session data. This can lead to local privilege escalation by overwriting shell configuration files, SSH keys, cron jobs, or systemd user services. Additionally, the lack of integrity verification on session files enables persistent prompt injection attacks by tampering with session data.