CERT-SEI

Interbase Server Contains Compiled-in Back Door Account

Original release date: January 10, 2001
Last revised: January 11, 2001
Source: CERT/CC

A complete revision history is at the end of this file.

Systems Affected

  • Borland/Inprise Interbase 4.x and 5.x
  • Open source Interbase 6.0 and 6.01
  • Open source Firebird 0.9-3 and earlier

Overview

Interbase is an open source database package that had previously been distributed in a closed source fashion by Borland/Inprise. Both the open and closed source versions of the Interbase server contain a compiled-in back door account with a known password.

I. Description

Interbase is an open source database package that is distributed by Borland/Inprise at http://www.borland.com/interbase/ and on SourceForge. The Firebird Project, an alternate Interbase package, is also distributed on SourceForge. The Interbase server for both distributions contains a compiled-in back door account with a fixed, easily located plaintext password. The password and account are contained in source code and binaries previously made available at the following sites:

This back door allows any local user or remote user able to access port 3050/tcp [gds_db] to manipulate any database object on the system. This includes the ability to install trapdoors or other trojan horse software in the form of stored procedures. In addition, if the database software is running with root privileges, then any file on the server's file system can be overwritten, possibly leading to execution of arbitrary commands as root.

This vulnerability was not introduced by unauthorized modifications to the original vendor's source. It was introduced by maintainers of the code within Borland. The back door account password cannot be changed using normal operational commands, nor can the account be deleted from existing vulnerable servers [see References].

This vulnerability has been assigned the identifier CAN-2001-0008 by the Common Vulnerabilities and Exposures (CVE) group:

http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2001-0008


The CERT/CC has not received reports of this back door being exploited at the current time. We do recommend, however, that all affected sites and redistributors of Interbase products or services follow the recommendations suggested in Section III, as soon as possible due to the seriousness of this issue.

II. Impact

Any local user or remote user able to access port 3050/tcp [gds_db] can manipulate any database object on the system. This includes the ability to install trapdoors or other trojan horse software in the form of stored procedures. In addition, if the database software is running with root privileges, then any file on the server's file system can be overwritten, possibly leading to execution of arbitrary commands as root.

III. Solution

Apply a vendor-supplied patch

Both Borland and The Firebird Project on SourceForge have published fixes for this problem. Appendix A contains information provided by vendors supplying these fixes. We will update the appendix as we receive more information. If you do not see your vendor's name, the CERT/CC did not hear from that vendor. Please contact your vendor directly.

Users who are more comfortable making their own changes in source code may find the new code available on SourceForge useful as well:

Block access to port 3050/tcp

This will not, however, prevent local users or users within a firewall's adminstrative boundary from accessing the back door account. In addition, the port the Interbase server listens on may be changed dynamically at startup.

Appendix A. Vendor Information

Borland

Please see:

IBPhoenix

The Firebird project uncovered serious security problems with InterBase. The problems are fixed in Firebird build 0.9.4 for all platforms. If you are running either InterBase V6 or Firebird 0.9.3, you should upgrade to Firebird 0.9.4.

These security holes affect all version of InterBase shipped since 1994, on all platforms.

For those who can not upgrade, Jim Starkey developed a patch program that will correct the more serious problems in any version of InterBase on any platform. IBPhoenix chose to release the program without charge, given the nature of the problem and our relationship to the community.

At the moment, name service is not set up to the machine that is hosting the patch, so you will have to use the IP number both for the initial contact and for the ftp download.

To start, point your browser at

http://firebird.ibphoenix.com/


Apple

The referenced database package is not packaged with Mac OS X or Mac OS X Server.

Fujitsu

Fujitsu's UXP/V operating system is not affected by this problem because we don't support the relevant database.

IBM

IBM's AIX operating system does not incorporate the Borland Interbase server software.

References

  1. VU#247371: Borland/Inprise Interbase SQL database server contains backdoor superuser account with known password CERT/CC, 01/10/2001, https://www.kb.cert.org/vuls/id/247371

Author: This document was written by Jeffrey S Havrilla. Feedback on this advisory is appreciated.

Copyright 2001 Carnegie Mellon University.

Revision History

January 10, 2001:  Initial release
January 11, 2001:  Changed Borland's link to direct one for patches
January 11, 2001:  Added vendor responses for IBM