Two vulnerabilities have been reported in Oracle Database Server, which can be exploited by malicious people to compromise a vulnerable system.

1) Requests to load and execute external libraries using "extproc" are not properly validated. This can be exploited by malicious users to execute any function in any DLL on the file system via the Oracle Listener, without requiring authentication.

2) A boundary error was introduced in the patch for vulnerability #1. This can be exploited to cause a stack-based buffer overflow when attempts to load external libraries via in the "CREATE LIBRARY" and "CREATE ANY LIBRARY" SQL functions are logged. Users who has been granted access to these functions could possibly exploit this to execute arbitrary code on the database server.

David Litchfield made a demonstration at the BlackHat Briefings proving that this can be exploited by anonymous users.

The vulnerabilities have been reported in versions 7, 8i and 9i.

Solution
Oracle has released patches:
Further details available to Secunia VIM customers

Provided and/or discovered by
David Litchfield and Chris Anley, Next Generation Security Software

Changelog
Further details available to Secunia VIM customers

Original Advisory
http://otn.oracle.com/deploy/security/pdf/2003alert57.pdf
http://www.nextgenss.com/advisories/ora-extproc.txt
http://www.ngssoftware.com/advisories/oraplsextproc.txt

Deep Links
Links available to Secunia VIM customers