ASI Sybase Security Alert: Buffer overflow in DBCC CHECKVERIFY

["Aaron C. Newman (Application Security, Inc.)" <anewman () appsecinc com>]

Sybase Adaptive Server buffer overflow in DBCC CHECKVERIFY

http://www.appsecinc.com/resources/alerts/sybase/02-0001.html

To determine if you should apply this hot fix, download AppDetective for
Sybase from http://www.sybasesecurity.net/products/appdetective/sybase/.

Risk level: High

Threat: Allows a non-privileged login to gain full control of the server

Versions Affected: Sybase Adaptive Server 12.0 and 12.5

Summary:
Sybase Adaptive Server provides a built-in function called DBCC
CHECKVERIFY. This function is used to verify the results of the most
recent run of DBCC CHECKSTORAGE.

Details:
DBCC CHECKVERIFY accepts a single parameter that is the name of the
database to check. DBCC CHECKVERIFY does not validate the length of the
string passed into the first parameter. This buffer overflow may allow
an attacker to run arbitrary code under the security context of the
server.

Below is an example of overflowing the buffer using the SQL tool
isql.exe.

1> declare @test varchar(16384)
2> select @test = replicate(‘A’, 16384)
3> DBCC CHECKVERIFY(@test)
4> go

Fix:
You should apply the following patches:
12.5.0.2 - 11/14/2002
12.0.0.6 ESD#1 - 11/5/2002

These patches can be downloaded from http://downloads.sybase.com/swd/swx

Thank you,
support () appsecinc com
Application Security, Inc.
phone: 212-490-6022
fax: 212-490-6456
-Protection Where It Counts-

----------------------------------------------------------------------
Application Security, Inc.
www.appsecinc.com

As pioneers in application security, we are an organization dedicated 
to the security, defense, and protection of one of the most commonly 
overlooked areas of security - the application layer. Application 
Security, Inc. provides solutions to proactively secure (penetration 
testing/vulnerability assessment), actively defend/monitor (intrusion 
detection), and protect (encryption) your most critical applications.
----------------------------------------------------------------------