The tsearch2 module in PostgreSQL 7.4 through 8.0.x declares the (1) dex_init, (2) snb_en_init, (3) snb_ru_init, (4) spell_init, and (5) syn_init functions as "internal" even when they do not take an internal argument, which allows attackers to cause

PostgreSQL 7.3.x through 8.0.x gives public EXECUTE access to certain character conversion functions, which allows unprivileged users to call those functions with malicious values, with unknown impact, aka the "Character conversion vulnerability."