The patches discussed below address two security vulnerabilities that are unrelated to each other except in the sense that both affect Index Server 2.0. The first vulnerability is a buffer overrun vulnerability. Index Server 2.0 has an unchecked buffer in a function that processes search requests. If an overly long value were provided for a particular search parameter, it would overrun the buffer. If the buffer were overrun with random data, it would cause Index Server to fail. If it were overrun with carefully selected data, code of the attacker’s choice could be made to run on the server, in the Local System security context.

The second vulnerability affects both Index Server 2.0 and Indexing Service in Windows 2000, and is a new variant of the “Malformed Hit-Highlighting” vulnerability discussed in Microsoft Security Bulletin MS00-006. The new variant has almost the same scope as the original vulnerability, but potentially exposes a new file type If an attacker provided an invalid search request, she could read “include” files residing on the web server. The new patch eliminates all known variants of the vulnerability.

Download locations for this patch located at: http://www.microsoft.com/technet/security/bulletin/MS01-025.asp