Overwrite any file via desname in Oracle Reports

Name Overwrite any file via desname in Oracle Reports
Systems Affected Oracle Reports 6.0, 6i, 9i, 10g
Severity High Risk
Category File overwrite
Vendor URL http://www.oracle.com
Author Alexander Kornbrust (ak at red-database-security.com)
Date 19 July 2005 (V 1.00)
Advisory AKSEC2003-005
Inital bug report 706 days ago

Details
Oracle Reports is Oracle's award-winning, high-fidelity enterprise reporting tool. It enables businesses to give immediate access to information to all levels within and outside of the organization in an unrivaled scalable and secure environment.
Oracle Reports, a component of the Oracle Application Server, is used by Oracle itself for the E-Business Suite. Many large customers are using Oracle Reports as reporting tool for their enterprise applications.

By specifing a special value for the parameter desname Oracle Reports can overwrite any file on the application server.
On Windows systems an attacker can overwrite any files (e.g. boot.ini) on the application server. On UNIX system an attacker can overwrite all files (e.g. opmn.xml) which belongs to the Oracle Application Server user.

This attack can be done with a simple URL.

TestURL:

Will be provided if a patch is available.

Workaround for Oracle Reports
Use URLRewrite to block potential dangerous URLs containing the desname parameter.

RewriteLog /anywhere/rewrite.log
RewriteEngine On
RewriteRule (.)desname(.)$ /forbidden.htm[R] [NC]

If you need the desname parameter in your URL you can create a new entry in the cgicmd.dat (e.g. mykey: desname=myoutput.pdf).

Don't forget to protect the content of your cgicmd.dat by setting the environment variable REPORTS_CGINODIAG=YES (see Metalink article 274858.1).

Affected systems
All versions of Oracle Reports are affected.
All applications using Oracle Reports (e.g. E-Business-Suite, …)

Patch Information
This bug is NOT FIXED with Critical Patch Update July 2005 (CPU July 2005). It seems that Oracle is NOT INTERESTED to fix this issue and provide patches for this issue.
If you believe you need a patch to protect your Oracle Application Server you should contact Oracle.

History
12-aug-2003 Oracle secalert was informed

26-sep-2003 Bug confirmed

15-apr-2005 Red-Database-Security informed Oracle secalert that this vulnerability will publish after CPU July 2005
Red-Database-Security offered Oracle more time if it is not possible to provide a fix ==> NO FEEDBACK.

12-jul-2005 Oracle published CPU July 2005 without fixing this issue

18-jul-2005 Red-Database-Security published this advisory