One of the features of Structured Query Language (SQL) in SQL Server 7.0 and 2000 is the ability to connect to remote data sources. One capability of this feature is the ability to use Ã????Ã???Ã??Ã?Â¢??ad hocÃ????Ã???Ã??Ã?Â¢?? connections to connect to remote data sources without setting up a linked server for less-often used data-sources. This is made possible through the use of OLE DB providers, which are low-level data source providers. This capability is made possible by invoking the OLE DB provider directly by name in a query to connect to the remote data source.
An unchecked buffer exists in the handling of OLE DB provider names in ad hoc connections. A buffer overrun could occur as a result and could be used to either cause the SQL Server service to fail, or to cause code to run in the security context of the SQL Server. SQL Server can be configured to run in various security contexts, and by default runs as a domain user. The precise privileges the attacker could gain would depend on the specific security context that the service runs in.
An attacker could exploit this vulnerability in one of two ways. They could attempt to load and execute a database query that calls one of the affected functions. Conversely, if a web-site or other database front-end were configured to access and process arbitrary queries, it could be possible for an attacker to provide inputs that would cause the query to call one of the functions in question with the appropriate malformed parameters.