RHSA-2011:1378 - Security Advisory

Topic

Updated postgresql84 packages that fix one security issue are now available
for Red Hat Enterprise Linux 5.

The Red Hat Security Response Team has rated this update as having moderate
security impact. A Common Vulnerability Scoring System (CVSS) base score,
which gives a detailed severity rating, is available from the CVE link in
the References section.

Description

PostgreSQL is an advanced object-relational database management system
(DBMS).

A signedness issue was found in the way the crypt() function in the
PostgreSQL pgcrypto module handled 8-bit characters in passwords when using
Blowfish hashing. Up to three characters immediately preceding a non-ASCII
character (one with the high bit set) had no effect on the hash result,
thus shortening the effective password length. This made brute-force
guessing more efficient as several different passwords were hashed to the
same value. (CVE-2011-2483)

Note: Due to the CVE-2011-2483 fix, after installing this update some users
may not be able to log in to applications that store user passwords, hashed
with Blowfish using the PostgreSQL crypt() function, in a back-end
PostgreSQL database. Unsafe processing can be re-enabled for specific
passwords (allowing affected users to log in) by changing their hash prefix
to "$2x$".

These updated postgresql84 packages upgrade PostgreSQL to version 8.4.9.
Refer to the PostgreSQL Release Notes for a full list of changes:

http://www.postgresql.org/docs/8.4/static/release.html

All PostgreSQL users are advised to upgrade to these updated packages,
which correct this issue. If the postgresql service is running, it will be
automatically restarted after installing this update.

Solution

Before applying this update, make sure all previously-released errata
relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
https://access.redhat.com/kb/docs/DOC-11259

Affected Products

• Red Hat Enterprise Linux Server 5 x86_64
• Red Hat Enterprise Linux Server 5 ia64
• Red Hat Enterprise Linux Server 5 i386
• Red Hat Enterprise Linux Workstation 5 x86_64
• Red Hat Enterprise Linux Workstation 5 i386
• Red Hat Enterprise Linux Desktop 5 x86_64
• Red Hat Enterprise Linux Desktop 5 i386
• Red Hat Enterprise Linux for IBM z Systems 5 s390x
• Red Hat Enterprise Linux for Power, big endian 5 ppc
• Red Hat Enterprise Linux Server from RHUI 5 x86_64
• Red Hat Enterprise Linux Server from RHUI 5 i386

Fixes

• BZ - 715025 - CVE-2011-2483 crypt_blowfish: 8-bit character mishandling allows different password pairs to produce the same hash

CVEs

• CVE-2011-2483

References

• https://access.redhat.com/security/updates/classification/#moderate
• http://www.postgresql.org/docs/8.4/static/release.html