SQL injection vulnerability in the PostgreSQL authentication module (mod_sql_postgres) for ProFTPD before 1.2.9rc1 allows remote attackers to execute arbitrary SQL and gain privileges by bypassing authentication or stealing passwords via the USER name.
http://www.debian.org/security/2003/dsa-338
http://lists.grok.org.uk/pipermail/full-disclosure/2003-June/005826.html