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        Oracle Security >> Oracle Security >> Checking EXECUTE IMMEDIATE in wrapped PLSQL
        
(Message started by: Pete Finnigan on Apr 2^nd, 2008, 12:44am)

Title: Checking EXECUTE IMMEDIATE in wrapped PLSQL
Post by Pete Finnigan on Apr 2^nd, 2008, 12:44am

A query on checking the content of wrapped PL/SQL code.

I'm considering the situation of an organisation with third party code in the form of wrapped PL/SQL packages. It would be useful to know that each package "did what it says on the box". That is, we know what tables it accesses and other packages it uses.

DBA_DEPENDENCIES can reveal most of that, and could show DBMS_SQL if they use that mechanism of Dynamic SQL. However it won't show up an EXECUTE IMMEDIATE.

Is there any way for a DBA to check for this (eg can it be done with DBMS_ASSERT or a scan of the DIANA code) ? Failing that, can it be audited ?

Title: Re: Checking EXECUTE IMMEDIATE in wrapped PLSQL
Post by Pete Finnigan on Apr 2^nd, 2008, 8:32am

Hi Gary,

Good question. A check for DBMS_ASSERT is only useful if the developers have actually used DBMS_ASSERT in their code. If its 10g then scanning the DIANA in the IDL%$ tables is not valid as the DIANA is not stored for package bodies, if you can compile the code then it is possible to get hold of the DIANA in RAM but then you need to understand the DIANA structure to make use of it, so this is a complete non-starter. There would seem to be two possible solutions, unwrap the code and review it, or run it and check v$SQL etc to find any dynamic SQL, PL/SQL or DDL run from in the code. This is also fraught with error as you have no idea if all code paths are executed.

The third option (ok I said 2) is to ask the vendor to allow you (one trusted person with the right skill and under an NDA) to review the code in clear text. Unwrapping the code to review it yourselves could invalidate support, break license......

Proper source code review is the best option

cheers

Pete

Title: Re: Checking EXECUTE IMMEDIATE in wrapped PLSQL
Post by Pete Finnigan on Apr 7^th, 2008, 2:45am

Thanks for the feedback.
I think it will come down to trusting the supplier (and keeping a good eye on the privileges of the account stuff runs under, and an extra eye on anything DEFINER rights).

Title: Re: Checking EXECUTE IMMEDIATE in wrapped PLSQL
Post by Pete Finnigan on Apr 7^th, 2008, 9:31am

Hi Gary,

I would ask the supplier anyway if you or a trusted third party can review the code under NDA, if they refuse then ask them to at least have a meeting to pose the "questions" you would pose as part of a technical review, but do it verbally rather than as part of a code review. I.e. sit them down and ask about use of execute immediate, ask for some samples, annonymised if necessary and comment on them. There is always a way to satisfy yourselves.

The situation is better, if you havent handed over the license fee yet and if there is another direct competitor to them that you can threaten them with.

cheers

Pete

Title: Re: Checking EXECUTE IMMEDIATE in wrapped PLSQL
Post by Pete Finnigan on Apr 10^th, 2008, 12:15am

The specific situation under consideration involved an upgrade to an existing app (from running on 9i to 10g) where all the 10g code would all be wrapped.
It is complicated by the fact the the supplier is in a different country (and I believe the coding is actually done in a third country). And there's patches coming through regularly too.
While I believe they probably would accept some form of review, the effort/costs for this situation wouldn't get past the bean-counters. A quickie script or routine to flag up danger signs would have been a different matter.

But I agree that in other situations the third-party review under a NDA would be an appropriate measure.