Oracle 10g extproc buffer overflow

NGSSoftware Insight Security Research Advisory

Name: Oracle 10g extproc buffer overflow
Systems Affected: Oracle 10g on all operating systems
Severity: High Risk
Vendor URL: http://www.oracle.com/
Author: David Litchfield [ davidl at ngssoftware.com ]
Relates to: http://www.nextgenss.com/advisories/oracle-01.txt
Date of Public Advisory: 23rd December 2004
Advisory number: #NISR23122004A
Advisory URL: http://www.ngssoftware.com/advisories/oracle23122004.txt

Description
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The Oracle database server supports PL/SQL, a programming language. PL/SQL
can execute external procedures via extproc. Over the past few years there
has been a number of vulnerabilities in this area:

http://www.nextgenss.com/advisories/oraplsextproc.txt
http://www.nextgenss.com/advisories/ora-extproc.txt

Extproc has been found to suffer from another buffer overflow vulnerability.

Details
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Oracle 10g imposes a length limit on the library name to be loaded by
extproc. However, this length limit can be evaded by passing environment
variables as part of the library name. Later on the environment variable is
expanded allowing the buffer overflow to be exploited. For example ‘$PATH’
is 5 characters long; this passes the length check. However, when expanded
‘$PATH’ becomes many more characters.
Exploitation depends upon the system setup but by trial and error a balance
can be found allowing arbitrary code to be executed. No user ID or password
is required to exploit this vulnerability.

Fix Information
***************
A patch (#68) was released for this problem by Oracle. See
http://metalink.oracle.com/ for more details. NGSSQuirreL for Oracle
(http://www.nextgenss.com/squirrelora.htm), can be used to assess whether
your Oracle servers are vulnerable to this.

About NGSSoftware
*****************
NGSSoftware design, research and develop intelligent, advanced application
security assessment scanners. Based in the United Kingdom, NGSSoftware have
offices in the South of London and the East Coast of Scotland. NGSSoftware’s
sister company NGSConsulting, offers best of breed security consulting
services, specialising in application, host and network security
assessments.

http://www.ngssoftware.com/

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