Microsoft offers plug for 'critical' SQL Server holes

[InfoSec News <isn () c4i org>]

http://www.nwfusion.com/news/2002/0725sqlholes.html

By Joris Evers
IDG News Service, 07/25/02 

Microsoft warned of five vulnerabilities in its SQL Server 2000
database product, the most serious of which could allow an attacker to
take over the server.

Deemed "critical" are three vulnerabilities in a feature that allows
users to host multiple copies of SQL Server on a single machine. Less
serious are two flaws in utilities for database consistency checks and
database replication, Microsoft said in two security bulletins
released late Wednesday.

Two buffer overrun flaws exist in the SQL Server Resolution Service,
which is used to direct users to the right TCP port when multiple SQL
Server copies are installed on one system. An attacker could get full
control over the system the database software is running on by
exploiting these flaws, Microsoft said.

A third flaw in the SQL Server Resolution Service is a denial of
service vulnerability. An attacker could initiate a never-ending cycle
of data packet exchanges between two or more database servers by
sending a specially crafted data packet to a mechanism designed to
check if a database server is online. The packet exchanges would
consume most if not all of the server resources, slowing performance,
Microsoft said.

Previous versions of SQL Server are not vulnerable as they do not
support multiple copies on one system and thus do not include the SQL
Server Resolution Service, Microsoft said.

Anybody with access to the SQL Server, for example via the Internet,
could exploit the flaws in the Resolution Service, Microsoft said.  
That makes those flaws more serious than the flaws in the database
consistency check and replication tools, which can only be exploited
by registered database users and administrators.

A buffer overrun vulnerability exists in several Database Consistency
Checkers that are part of database maintenance tools. A user assigned
the already privileged db_owner or db_ddladmin role on one database
could exploit the flaw to gain control over the complete server,
Microsoft said.

The database replication function has a so-called SQL Injection
Vulnerability that could allow an attacker to gain control over the
server. It is exploitable by anybody with user privileges on the SQL
server, but requires a special purpose user account to be enabled.  
This SQL Server Agent Proxy Account is disabled by default and can
only be enabled by a server administrator, Microsoft said.

Patches to fix the vulnerabilities are available from Microsoft's
TechNet Web site. Users should immediately patch the SQL Server
Resolution Service holes, while the other patch should be considered,
Microsoft said.



-
ISN is currently hosted by Attrition.org

To unsubscribe email majordomo () attrition org with 'unsubscribe isn'
in the BODY of the mail.