A vulnerability in Microsoft SQL Server may allow an attacker to hijack a named pipe. An attacker may be able to leverage this vulnerability to gain elevated privileges.
Microsoft describes a named pipe as, "a specifically named one-way or two-way channel for communication between a pipe server and one or more pipe clients." Microsoft SQL Server does not correctly check named pipes. Quoting from MS03-031, "The vulnerability results because of a flaw in the checking method used by SQL Server when a client establishes an authenticated logon by using a named pipe."
A local attacker may be able to hijack a named pipe, which may result in privilege elevation. Quoting from MS03-031, "This could allow an attacker to gain control of the named pipe at the same permission level as the user attempting to connect. If the user connecting remotely had higher access rights than the attacker, the attacker could assume those rights when the named pipe was compromised."
Apply a patch.
This vulnerability was discovered by Andreas Junstream of @Stake. The CERT/CC thanks Microsoft for providing Microsoft Security Bulletin MS03-031, upon which the majority of this document is based.
This document was written by Ian A Finlay.
|Date First Published:||2003-07-24|
|Date Last Updated:||2003-07-25 17:23 UTC|