AUSCERT External Security Bulletin Redistribution

                ESB-2001.111 -- FreeBSD-SA-01:26.interbase
                    interbase contains remote backdoor
                               13 March 2001


        AusCERT Security Bulletin Summary

Product:                interbase
Vendor:                 FreeBSD Ports Collection
Operating System:       FreeBSD
Impact:                 Root Compromise
                        Create Arbitrary Files
Access Required:        Remote

Ref:                    ESB-2001.017

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FreeBSD-SA-01:26                                           Security Advisory
                                                                FreeBSD, Inc.

Topic:          interbase contains remote backdoor

Category:       ports
Module:         interbase
Announced:      2001-03-12
Credits:        Firebird project <http://firebird.sourceforge.net>
Affects:        Ports collection prior to the correction date.
Corrected:      See below.
Vendor status:  No update released
FreeBSD only:   NO

I.   Background

Interbase is a SQL database server from Borland.

II.  Problem Description

The interbase software contains a remote backdoor account, which was
apparently introduced by the vendor in 1992.  The interbase source
code has recently been released and is the basis for a derivative
project called firebird, who are credited with discovering the

The backdoor account has full read and write access to databases
stored on the server, and also gives the ability to write to arbitrary
files on the server as the user running the interbase server (usually
user root).  Remote attackers may connect to the database on TCP port

The interbase port is not installed by default, nor is it "part of
FreeBSD" as such: it is part of the FreeBSD ports collection, which
contains nearly 4700 third-party applications in a ready-to-install
format.  The ports collections shipped with FreeBSD 3.5.1 and 4.2
contain this problem since it was discovered after the releases.

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

Remote users who can connect to the interbase database server can
obtain full access to all databases using a backdoor account built
into the server itself.  This account cannot be disabled.

If you have not chosen to install the interbase port/package, then
your system is not vulnerable to this problem.

IV.  Workaround

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

2) Use packet filters on your perimeter firewalls, or ipfw(8)/ipf(8)
on the interbase server to prevent connections from untrusted systems
to TCP port 3050 on the interbase server.  Note that local users, or
arbitrary users on systems permitted to connect to the TCP port can
still access the backdoor account.

3) Migrate to the firebird database, which is an open-source
derivative of the interbase software which does not contain the
backdoor account.

V.   Solution

The FreeBSD port of interbase is not provided by Borland -- it is
provided in binary form from Rios Corporation -- and there does not
appear to be a patch available for the security vulnerability.
Therefore there is currently no complete solution to this security
vulnerability; see the previous section for possible workarounds.
Version: GnuPG v1.0.4 (FreeBSD)
Comment: For info see http://www.gnupg.org


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