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."

Updated postgresql packages that fix several security vulnerabilities and risks of data loss are now available.

This update has been rated as having moderate security impact by the Red Hat Security Response Team.

PostgreSQL is an advanced Object-Relational database management system (DBMS) that supports almost all SQL constructs (including transactions, subselects and user-defined types and functions).

The PostgreSQL community discovered two distinct errors in initial system catalog entries that could allow authorized database users to crash the database and possibly escalate their privileges. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the names CVE-2005-1409 and CVE-2005-1410 to these issues.

Although installing this update will protect new (freshly initdb'd) database installations from these errors, administrators MUST TAKE MANUAL ACTION to repair the errors in pre-existing databases. The appropriate procedures are explained at http://www.postgresql.org/docs/8.0/static/release-7-4-8.html for Red Hat Enterprise Linux 4 users, or http://www.postgresql.org/docs/8.0/static/release-7-3-10.html for Red Hat Enterprise Linux 3 users.

This update corrects several problems that might occur while trying to upgrade a Red Hat Enterprise Linux 3 installation (containing rh-postgresql packages) to Red Hat Enterprise Linux 4 (containing postgresql packages). These updated packages correctly supersede the rh-postgresql packages.

The original release of Red Hat Enterprise Linux 4 failed to initialize the database correctly if started for the first time with SELinux in enforcement mode. This update corrects that problem.

If you already have a nonfunctional database in place, shut down the postgresql service if running, install this update, then do 'sudo rm
-rf /var/lib/pgsql/data' before restarting the postgresql service.

This update also solves the problem that the PostgreSQL server might fail to restart after a system reboot, due to a stale lockfile.

This update also corrects a problem with wrong error messages in libpq, the postgresql client library. The library would formerly report kernel error messages incorrectly when the locale setting was not C.

This update also includes fixes for several other errors, including two race conditions that could result in apparent data inconsistency or actual data loss.

All users of PostgreSQL are advised to upgrade to these updated packages and to apply the recommended manual corrections to existing databases.

The postgresql development team reports :

The more severe of the two errors is that the functions that support client-to-server character set conversion can be called from SQL commands by unprivileged users, but these functions are not designed to be safe against malicious choices of argument values. This problem exists in PostgreSQL 7.3.* through 8.0.*. The recommended fix is to disable public EXECUTE access for these functions. This does not affect normal usage of the functions for character set conversion, but it will prevent misuse.

The other error is that the contrib/tsearch2 module misdeclares several functions as returning type 'internal' when they do not have any 'internal' argument. This breaks the type safety of 'internal' by allowing users to construct SQL commands that invoke other functions accepting 'internal' arguments. The consequences of this have not been investigated in detail, but it is certainly at least possible to crash the backend.

It was discovered that unprivileged users were allowed to call internal character conversion functions. However, since these functions were not designed to be safe against malicious choices of argument values, this could potentially be exploited to execute arbitrary code with the privileges of the PostgreSQL server (user 'postgres'). (CAN-2005-1409)

Another vulnerability was found in the 'tsearch2' module of postgresql-contrib. This module declared several functions as internal, although they did not accept any internal argument; this breaks the type safety of 'internal' by allowing users to construct SQL commands that invoke other functions accepting 'internal' arguments. This could eventually be exploited to crash the server, or possibly even execute arbitrary code with the privileges of the PostgreSQL server. (CAN-2005-1410)

These vulnerabilities must also be fixed in all existing databases when upgrading. The post-installation script of the updated package attempts to do this automatically; if the package installs without any error, all existing databases have been updated to be safe against above vulnerabilities. Should the installation fail, please contact the Ubuntu security team (security@ubuntu.com) immediately.

Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

A number of vulnerabilities were found and corrected in the PostgreSQL DBMS :

Two serious security errors have been found in PostgreSQL 7.3 and newer releases. These errors at least allow an unprivileged database user to crash the backend process, and may make it possible for an unprivileged user to gain the privileges of a database superuser.

Functions that support client-to-server character set conversion can be called from SQL commands by unprivileged users, but these functions are not designed to be safe against malicious choices of argument values. (CVE-2005-1409)

The contrib/tsearch2 module misdeclares several functions as returning type 'internal' when they do not have any 'internal' argument. This breaks the type safety of 'internal' by allowing users to construct SQL commands that invoke other functions accepting 'internal' arguments. (CVE-2005-1410)

These vulnerabilities must also be fixed in all existing databases when upgrading. The post-installation script of the updated postgresql-server package attempts to do this automatically.

The updated packages have been patched to correct these problems.

The remote Redhat Enterprise Linux 4 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2005:433 advisory.

    PostgreSQL is an advanced Object-Relational database management system     (DBMS) that supports almost all SQL constructs (including     transactions, subselects and user-defined types and functions).

    The PostgreSQL community discovered two distinct errors in initial system     catalog entries that could allow authorized database users to crash the     database and possibly escalate their privileges.  The Common     Vulnerabilities and Exposures project (cve.mitre.org) has assigned the     names CAN-2005-1409 and CAN-2005-1410 to these issues.

    Although installing this update will protect new (freshly initdb'd)     database installations from these errors, administrators MUST TAKE MANUAL     ACTION to repair the errors in pre-existing databases.  The appropriate     procedures are explained at     http://www.postgresql.org/docs/8.0/static/release-7-4-8.html     for Red Hat Enterprise Linux 4 users, or     http://www.postgresql.org/docs/8.0/static/release-7-3-10.html     for Red Hat Enterprise Linux 3 users.

    This update corrects several problems that might occur while trying to     upgrade a Red Hat Enterprise Linux 3 installation (containing rh-postgresql     packages) to Red Hat Enterprise Linux 4 (containing postgresql packages).
    These updated packages correctly supersede the rh-postgresql packages.

    The original release of Red Hat Enterprise Linux 4 failed to initialize the     database correctly if started for the first time with SELinux in     enforcement mode. This update corrects that problem.

    If you already have a nonfunctional database in place, shut down the     postgresql service if running, install this update, then do sudo rm -rf     /var/lib/pgsql/data before restarting the postgresql service.

    This update also solves the problem that the PostgreSQL server might fail     to restart after a system reboot, due to a stale lockfile.

    This update also corrects a problem with wrong error messages in libpq,     the postgresql client library.  The library would formerly report kernel     error messages incorrectly when the locale setting was not C.

    This update also includes fixes for several other errors, including two     race conditions that could result in apparent data inconsistency or actual     data loss.

    All users of PostgreSQL are advised to upgrade to these updated packages     and to apply the recommended manual corrections to existing databases.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote host is affected by the vulnerability described in GLSA-200505-12 (PostgreSQL: Multiple vulnerabilities)

    PostgreSQL gives public EXECUTE access to a number of character     conversion routines, but doesn't validate the given arguments     (CAN-2005-1409). It has also been reported that the contrib/tsearch2     module of PostgreSQL misdeclares the return value of some functions as     'internal' (CAN-2005-1410).
  Impact :

    An attacker could call the character conversion routines with specially     setup arguments to crash the backend process of PostgreSQL or to     potentially gain administrator rights. A malicious user could also call     the misdeclared functions of the contrib/tsearch2 module, resulting in     a Denial of Service or other, yet uninvestigated, impacts.
  Workaround :

    There is no known workaround at this time.

According to its banner, the version of PostgreSQL installed on the remote host may suffer from the following vulnerabilities :

  - Character Conversion Vulnerability     Unprivileged users can call functions supporting client-     server character set conversion from SQL commands even     though those functions do not validate their arguments.

  - tsearch2 Vulnerability     If installed, the 'contrib/tsearch2' module permits     users     to at a minimum crash the backend because it misdeclares     several functions as returning type 'internal' when in     fact they do not have any 'internal' argument.

The remote host is running PostgreSQL, an open source relational database.  This version is vulnerable to a number of flaws.  Specifically, the following functions are directly accessible to remote users:
dex_init()
snb_en_init()
snb_ru_init()
spell_init()
syn_init()

An attacker calling these functions can submit queries that lead to compromise of confidential data or execution of arbitrary code on the remote database server. 

ID	Name	Product	Family	Severity
21826	CentOS 3 / 4 : postgresql (CESA-2005:433)	Nessus	CentOS Local Security Checks	high
21425	FreeBSD : postgresql -- character conversion and tsearch2 vulnerabilities (486aff57-9ecd-11da-b410-000e0c2e438a)	Nessus	FreeBSD Local Security Checks	high
20506	Ubuntu 4.10 / 5.04 : postgresql vulnerabilities (USN-118-1)	Nessus	Ubuntu Local Security Checks	high
18411	Mandrake Linux Security Advisory : postgresql (MDKSA-2005:093)	Nessus	Mandriva Local Security Checks	high
18408	RHEL 4 : postgresql (RHSA-2005:433)	Nessus	Red Hat Local Security Checks	critical
18271	GLSA-200505-12 : PostgreSQL: Multiple vulnerabilities	Nessus	Gentoo Local Security Checks	high
18202	PostgreSQL < 8.0.3 Multiple Vulnerabilities	Nessus	Databases	medium
2876	PostgreSQL < 8.0.3 Incorrect Function Declaration	Nessus Network Monitor	Database	medium

Detections

Analytics

CVE-2005-1409

critical

Tenable Plugins

high

high

high

high

critical

high

medium

medium