Alert: Microsoft Security Bulletin - MS02-043

From: Russ (Russ.Cooper@RC.ON.CA)
Date: 08/15/02


Date:         Thu, 15 Aug 2002 16:51:08 -0400
From: Russ <Russ.Cooper@RC.ON.CA>
To: NTBUGTRAQ@LISTSERV.NTBUGTRAQ.COM

http://www.microsoft.com/technet/security/bulletin/MS02-043.asp

Cumulative Patch for SQL Server (Q316333)

Originally posted: August 14, 2002

Summary

Who should read this bulletin: System administrators using Microsoft® SQL Server(tm) 7.0 and 2000 and Microsoft Desktop Engine 1.0 and 2000.

Impact of vulnerability: Elevation of privilege.

Maximum Severity Rating: Moderate

Recommendation: System administrators should apply the patch to affected systems.

Affected Software:
- Microsoft SQL Server 7.0
- Microsoft Desktop Engine (MSDE) 1.0
- Microsoft SQL Server 2000
- Microsoft Desktop Engine (MSDE) 2000

Technical description:

This is a cumulative patch that includes the functionality of all previously released patches for SQL Server 7.0 and SQL Server 2000. In addition, it eliminates a newly discovered vulnerability.

SQL Server 7.0 and SQL Server 2000 provide for extended stored procedures, which are external routines written in programming languages such as C or C#. These procedures appear as normal stored procedures to users and can be invoked and executed just like normal stored procedures. By default, SQL Server 7.0 and SQL Server 2000 ship with a number of extended stored procedures which are used for various helper functions.

Some of the Microsoft-provided extended stored procedures that have the ability to reconnect to the database as the SQL Server service account have a flaw in common - namely, they have weak permissions that can allow non-privileged users to execute them. Because these extended stored procedures can be made to run with administrator privileges on the database, it is thus possible for a non-privileged user to run stored procedures on the database with administrator privileges.

An attacker could exploit this vulnerability in one of two ways. The attacker could attempt to load and execute a database query that calls one of the affected extended store procedures. Alternately, if a web-site or other database front-end were configured to access and process arbitrary queries, it could be possible for the attacker to provide inputs that would cause the query to call one of the functions in question with the appropriate malformed parameters.

Mitigating factors:
- The effect of exploiting the vulnerability would depend on the specific configuration of the SQL Server service. SQL Server can be configured to run in a security context chosen by the administrator. By default, this context is as a domain user. If the rule of least privilege has been followed, it would minimize the amount of damage an attacker could achieve.
- The vector for exploiting this vulnerability could be blocked by following best practices. Specifically, untrusted users should not be able to load and execute queries of their choice on a database server. In addition, publicly accessible database queries should filter all inputs prior to processing.

Vulnerability identifier: CAN-2002-0721

This email is sent to NTBugtraq automatically as a service to my subscribers. Since its programmatically created, and since its been a long time since anyone paid actual money for my programming skills, it may or may not look that good...;-]

I can only hope that the information it does contain can be read well enough to serve its purpose.

Cheers,
Russ - Surgeon General of TruSecure Corporation/NTBugtraq Editor



Relevant Pages

  • Alert: Microsoft Security Bulletin - MS03-031
    ... Cumulative Patch for Microsoft SQL Server ... This vulnerability would not allow an attacker to run arbitrary code or elevate their permissions, but it may still be possible for a denial of service condition to exist that would require that the server be restarted to restore functionality. ...
    (NT-Bugtraq)
  • Alert: Microsoft Security Bulletin - MS02-034
    ... Database administrators using Microsoft® SQL Server(tm) or Microsoft SQL Server Desktop Engine 2000. ... An attacker would need to already possess significant rights on the server in order to exploit the vulnerability, as only Bulk Admins and full administrators have the ability to load and run queries that invoke the vulnerable procedure. ...
    (NT-Bugtraq)
  • Alert: Microsoft Security Bulletin - MS02-061
    ... Elevation of Privilege in SQL Server Web Tasks ... Microsoft SQL Server 7.0 ... Exploiting this vulnerability could allow the attacker to escalate privileges to the level of the SQL Server service account. ...
    (NT-Bugtraq)
  • [NT] SQL Server 2000 Buffer Overflows and SQL Injection Vulnerabilities
    ... allow maintenance and other operations to be performed on a SQL Server, ... fixed database role can run this command. ... Buffer Overrun Vulnerability in Database Consistency Checkers: ... privileges, and only should be granted to trusted users. ...
    (Securiteam)
  • [NT] Cumulative Patch for SQL Server
    ... The following security advisory is sent to the securiteam mailing list, and can be found at the SecuriTeam web site: http://www.securiteam.com ... released patches for SQL Server 2000. ... * A buffer overrun vulnerability in a procedure used to encrypt SQL ... An attacker who was able to successfully ...
    (Securiteam)