AUSCERT External Security Bulletin Redistribution

              ESB-2002.007 -- FreeBSD-SA-02:03.mod_auth_pgsql
                 mod_auth_pgsql port authentication bypass
                              8 January 2002


        AusCERT Security Bulletin Summary

Product:                mod_auth_pgsql Apache Module
Vendor:                 FreeBSD Ports Collection
Operating System:       FreeBSD
Impact:                 Inappropriate Access
Access Required:        Remote

- --------------------------BEGIN INCLUDED TEXT--------------------


FreeBSD-SA-02:03                                            Security Advisory
                                                                FreeBSD, Inc.

Topic:          mod_auth_pgsql port authentication bypass

Category:       ports
Module:         mod_auth_pgsql
Announced:      2002-01-04
Credits:        RUS CERT <URL:http://cert.uni-stuttgart.de/>
Affects:        Ports collection prior to the correction date
Corrected:      2001-10-02 11:33:49 UTC
FreeBSD only:   NO

I.   Background

mod_auth_pgsql is an Apache module which allows the Apache web server
to use a PostgreSQL database for user and/or group authentication.

II.  Problem Description

The mod_auth_pgsql port, versions prior to mod_auth_pgsql-0.9.9,
contain a vulnerability that may allow a remote user to cause
arbitrary SQL code to be execute.  mod_auth_pgsql constructs a SQL
statement to be executed by the PostgreSQL server in order to lookup
user information.  The username given by the remote user is inserted
into the SQL statement without any quoting or other safety checks.

The mod_auth_pgsql port is not installed by default, nor is it "part of
FreeBSD" as such: it is part of the FreeBSD ports collection, which
contains over 6000 third-party applications in a ready-to-install
format. The ports collection shipped with FreeBSD 4.4 contains this
problem since it was discovered after the release.

FreeBSD makes no claim about the security of these third-party
applications, although an effort is underway to provide a security
audit of the most security-critical ports.

III. Impact

A remote user may insert arbitrary SQL code into the username during
authentication, leading to several exploit opportunities.  In
particular, the attacker may cause mod_auth_pgsql to use a known fixed
password hash for user verification, allowing him to authenticate as
any user and obtain unauthorized access to web server data.

IV.  Workaround

1) Deinstall the mod_auth_pgsql port/package if you have it installed.

V.   Solution

1) Upgrade your entire ports collection and rebuild the port.

2) Deinstall the old package and install a new package dated after the
correction date, obtained from the following directories:


Packages are not automatically generated for the alpha architecture at
this time due to lack of build resources.

3) Download a new port skeleton for the mod_auth_pgsql port from:


and use it to rebuild the port.

4) Use the portcheckout utility to automate option (3) above. The
portcheckout port is available in /usr/ports/devel/portcheckout or the
package can be obtained from:


VI.  Correction details

The following list contains the $FreeBSD$ revision numbers of each
file that was corrected in the FreeBSD source

Path                                                             Revision
- - -------------------------------------------------------------------------
ports/www/mod_auth_pgsql/Makefile                                     1.3
ports/www/mod_auth_pgsql/distinfo                                     1.2
- - -------------------------------------------------------------------------

VII. References

Version: GnuPG v1.0.6 (FreeBSD)
Comment: For info see http://www.gnupg.org


- --------------------------END INCLUDED TEXT--------------------

You have received this e-mail bulletin as a result of your organisation's
registration with AusCERT. The mailing list you are subscribed to is
maintained within your organisation, so if you do not wish to continue
receiving these bulletins you should contact your local IT manager. If
you do not know who that is, please send an email to auscert@auscert.org.au
and we will forward your request to the appropriate person.

This security bulletin is provided as a service to AusCERT's members.  As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content.  The decision to use any or all of this information is
the responsibility of each user or organisation, and should be done so in
accordance with site policies and procedures.

NOTE: This is only the original release of the security bulletin.  It may
not be updated when updates to the original are made.  If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the original authors to ensure that the information is still current.

Contact information for the authors of the original document is included
in the Security Bulletin above.  If you have any questions or need further
information, please contact them directly.

Previous advisories and external security bulletins can be retrieved from:


If you believe that your system has been compromised, contact AusCERT or
your representative in FIRST (Forum of Incident Response and Security

Internet Email: auscert@auscert.org.au
Facsimile:	(07) 3365 7031
Telephone:	(07) 3365 4417 (International: +61 7 3365 4417)
		AusCERT personnel answer during Queensland business hours
		which are GMT+10:00 (AEST).
		On call after hours for emergencies.

Version: 2.6.3i
Charset: noconv
Comment: ftp://ftp.auscert.org.au/pub/auscert/AUSCERT_PGP.key