High Risk Vulnerability in Oracle TNS Listener
October 17th, 2007NGSSoftware 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
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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
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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. 0×1FFFF) 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
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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/cpuoct2007.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.php
About NGSSoftware
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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,
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http://www.ngssoftware.com/
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