Sunday, January 25, 2015

On Demand Process Bug

In my last post I wrote about security of on demand application processes. While I was testing this I've noticed a bug in APEX version 4.2.6.00.03 and APEX 5 EA2 (probably in some older versions too).

If you have on demand application process (without authorization scheme) and call it from public page (e.g. login page 101) you'll get additional unwanted data in response message.

For example, if you create public on demand application process like this that outputs some string like"OK":

and call it in some on load dynamic action on public page (like login page):

When you take a look at console window you'll see additional data with "OK" string:

If you are expecting that your message is returning something in JSON format you'll get an JS error on page.

I've reported a bug to APEX team and they've fix it for version 5.

Friday, January 23, 2015

Secure your On Demand processes

By default when you create On Demand application process there is no authorization scheme selected:


and that makes your On Demand processes very vulnerable and publicly available.

For example, if you create On Demand application process without authorization scheme named DUMMY that creates record in DEPT table:


it can easily be called from browser console window without being logged in into application (e.g. on login page 101) by executing this JS statement:
apex.server.process ("DUMMY" 
                    ,{x01: "IT",x02: "LOS ANGELES"}
                    ,{dataType:"text"}
                    );

Table before executed JS statement:
DEPTNODNAMELOC
10ACCOUNTINGNEW YORK
20RESEARCHDALLAS
30SALESCHICAGO
40OPERATIONSBOSTON

Table after executed JS statement:
DEPTNODNAMELOC
10ACCOUNTINGNEW YORK
20RESEARCHDALLAS
30SALESCHICAGO
40OPERATIONSBOSTON
50ITLOS ANGELES

If you change authorization scheme of your On Demand application process to Must Not Be Public User:

it will not be publicly available and unauthorized users will not be able to call it without logging in into application.

Environment: APEX 4.2.5.00.08 and Oracle XE 11.2.0.2.0 database.

Thursday, September 11, 2014

Remove Annoying Login Message

If you are annoyed by login message "...Please wait 5 seconds to login again..." that apears in APEX 4.2.* after failed login attempt you're lucky for reading this post. There is an easy way to switch it off.

Login to APEX Builder like instance admin and go to Manage Instance > Security option. Find General Login Control region and set property Delay after failed login attempts in Seconds to 0.




Tested with APEX 4.2.5.00.08 and Oracle XE 11.2.0.2.0 database.

Sunday, March 9, 2014

View Item Session State from PL/SQL IDE

One and a half year ago I had a post about viewing data from APEX collections from your favorite PL/SQL IDE (PL/SQL Developer, TOAD, SQL Developer...). Similar to that you can view current item session state. First step should be getting grants from some internal APEX packages (executing as sys user):

grant execute on apex_040200.wwv_flow_security to test;
grant execute on apex_040200.wwv_flow_session_state to test;

After that you have to register application and session ID in your PL/SQL IDE (running in parsing schema, e.g. test):

begin
   -- Set Application ID       
   apex_040200.wwv_flow_security.g_flow_id := 121;
      
   -- Set Session ID  
   apex_040200.wwv_flow_security.g_instance := 802090201361;   
end; 

Any time you want to see current session state from some item you have to refresh current session state values by executing:

begin   
   -- Refresh Item Session State Values
   apex_040200.wwv_flow_session_state.fetch_into_substitution_cache(true);
end;

After that you can see value from any item in current session using function v or apex_util.get_session_state, for example:

select v('P1_TEST') from dual

Tested with APEX 4.2.4.00.08 and Oracle XE 11.2.0.2.0 database.

NOTE: It wouldn't be a good idea to give these grants on production instances. :)


Sunday, November 10, 2013

APEX Security Holes - Page Items to Submit Property (Part 1)

I've discovered some interesting things about APEX checksum and item session state. I'll show you some tricks (security holes) and how to avoid them.

Suppose you are authorized to see only departments 10 and 30. Your query should look like this:


  SELECT deptno, dname 
    FROM dept 
   WHERE deptno in (10,30)


and the report page:

where link "View Employees" points to page where you can see all employees in selected department. SQL on that page should look like this:


  SELECT ename    as "Name"
       , job      as "Job"
       , hiredate as "Hire Date"
       , sal      as "Salary"
       , deptno
   FROM emp
  WHERE deptno = :P2_DEPTNO


On this page checksum is turned on so you can't manipulate with URL and change department number:


The link that points to second page should look like this:


  f?p=150:2:6476219590424::NO:2:P2_DEPTNO:30&cs=3DBC2DC62D86556DA878EBB2420F038C0


But if you accidently put item that is used for filtering employees (in my case P2_DEPTNO) to "Page Items To Submit" property of report region there is an easy way to change it and to see employees that you are not supposed to see.


If you clicked on Accounting department on first page you should see 3 employees:





















After that, you just have to open your favorite web debug tool, in my case FireBug, and run following code (where R12587121803287243 is ID of your report region) that sets value of item P2_DEPTNO to 20 and refreshes report region:
















Voilà! Now you should see employees in department 20:
























The refresh of region can be done in other ways. For example, by clicking on pagination.
To see if report region have some items to submit in report properties you can execute this line in FireBug console:


  console.log(apex.widget.report.gPageItemsToSubmit);


When you change session state protection property of item P2_DEPTNO to "Checksum Required - ..." refresh of report will not work but neither the pagination on that report.

So watch out with property "Page Items to Submit"!!

In next post I'll show you how can you easily change item session state on some other ways.

Tested on APEX 4.2.3.00.08.

Monday, October 14, 2013

Monday, September 16, 2013

Presentation on Croatian Oracle User Group conference (HROUG 2013)

This year I'll have presentation on HROUG (Croation Oracle User Group) conference that will take place in Rovinj from October 15th - 19th 2013. There will be some great presentations held by Tomas Kyte, Deneš Kubiček, Jože Senegačnik, Melanie Cafrrey and many more...


My presentation is about hybrid mobile applications in APEX.

I'm looking forward to it!