PostgreSQL is an advanced object-relational database management system(DBMS).A signedness issue was found in the way the crypt() function in thePostgreSQL pgcrypto module handled 8-bit characters in passwords when usingBlowfish hashing. Up to three characters immediately preceding a non-ASCIIcharacter (one with the high bit set) had no effect on the hash result,thus shortening the effective password length. This made brute-forceguessing more efficient as several different passwords were hashed to thesame value. (CVE-2011-2483)Note: Due to the CVE-2011-2483 fix, after installing this update some usersmay not be able to log in to applications that store user passwords, hashedwith Blowfish using the PostgreSQL crypt() function, in a back-endPostgreSQL database. Unsafe processing can be re-enabled for specificpasswords (allowing affected users to log in) by changing their hash prefixto "$2x$".For Red Hat Enterprise Linux 6, the updated postgresql packages upgradePostgreSQL to version 8.4.9. Refer to the PostgreSQL Release Notes for afull list of changes:http://www.postgresql.org/docs/8.4/static/release.htmlFor Red Hat Enterprise Linux 4 and 5, the updated postgresql packagescontain a backported patch.All PostgreSQL users are advised to upgrade to these updated packages,which correct this issue. If the postgresql service is running, it will beautomatically restarted after installing this update.