NGSSoftware Insight Security Research Advisory

Name: Oracle TNS Listener DoS and/or remote memory inspection
Systems Affected: Oracle 8.1.7.4, 10g Release 2 and 1, Oracle 9
Severity: High
Vendor URL: http://www.oracle.com/ 
Author: David Litchfield [ davidl@ngssoftware.com ] 
Reported: 22nd June 2006
Date of Public Advisory: 17th October 2007
Advisory number: #NISR17102007C


Description
***********
The TNS Listener can be crashed by an attacker causing a Denial of Service;
alternatively the attacker can use the same flaw to expose memory contents
remotely. This may reveal sensitive information.
 
Details
*******
There is a bug in GIOP service that can allow an attacker to crash the TNS
Listener and/or dump memory. A DWORD in the connect GIOP packet is trusted
as the  size of the data in the packet. By setting this to a large value
(e.g. 0x1FFFF) causes the listener to allocate this much memory then attempt
to copy this  much data to it - which eventually leads to a read access
violation because the source data is less than this number and the process
lands in uninitialized  memory. If the attacker uses a smaller number, e.g.
0xFFFF they can dump this many bytes from memory. This may reveal sensitive
information such as the TNS  Listener password.

Fix Information
***************
Oracle was alerted to this flaw on the 22nd of June 2006. A patch has now
been made available:

http://www.oracle.com/technology/deploy/security/critical-patch-updates/cpuo 
ct2007.html

NGSSQuirreL for Oracle, an advanced vulnerability assessment scanner
designed specifically for Oracle, can be used to accurately determine
whether your servers is vulnerable to this flaw. More information about
NGSSQuirreL for Oracle can be found here:

http://www.ngssoftware.com/products/database-security/ngs-squirrel-oracle.ph 
p

 
About NGSSoftware
*****************
NGSSoftware develops vulnerability assessment and compliancy tools for
database servers including Oracle, Microsoft SQL Server, DB2, Sybase and
Informix.  Headquartered in the United Kingdom NGS has offices in London,
St. Andrews (UK), Brisbane, and Perth (Australia) and seattle in the United
States;  NGSConsulting provide services to some of the largest and most
demanding organizations around the globe.
http://www.ngssoftware.com/ 
Telephone +44 208 401 0070
Fax +44 208 401 0076
enquiries@ngssoftware.com 

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