CVE-2006-0553: Undefined Security Weakness

PostgreSQL 8.1.0 through 8.1.2 allows authenticated database users to gain additional privileges via "knowledge of the backend protocol" using a crafted SET ROLE to other database users, a different vulnerability than CVE-2006-0678...

postgresql81-server -- SET ROLE privilege escalation

The PostgreSQL team reports: Due to inadequate validity checking, a user could exploit the special case that SET ROLE normally uses to restore the previous role setting after an error. This allowed ordinary users to acquire superuser status, for example...