Secunia

Three vulnerabilities has been identified in Microsoft SQL Server and MSDE allowing local users to escalate their privileges or cause a Denial of Service.

1) Malicious users can hijack the connection of another user who is attempting to authenticate through the named pipe. This allows the malicious user to perform actions with the privileges of the other user.

2) It is possible to cause a Denial of Service by sending large packets to the named pipe on the host running SQL Server or MSDE. This does not require the malicious person to be authenticated.

3) A malicious user who is logged on to the system running SQL Server or MSDE may cause a buffer overflow by sending a malicious packet to the local procedure call (LPC) port on the system. This could be exploited to escalate privileges to those of the SQL Server.

Solution
Patches are available:
Further details available in Customer Area

Provided and/or discovered by
Andreas Junstream, @Stake

Original Advisory
http://www.microsoft.com/technet/security/bulletin/MS03-031.asp

Deep Links
Links available in Customer Area