2. Incomplete Mediation
Incomplete mediation occurs when the application
accepts incorrect data from the user
What happens if someone fills in:
DOB: 98764874236492483649247836489236492
•Buffer overflow?
DOB: ’; DROP DATABASE clients;
•SQL injection?
3. Cont…
If data exchanged between components of the system (such as
client and server) is compromised or altered system may fail.
Example: Form data submitted from a web browser may be altered
before reaching the server
The data is exchanged between a web client and server as part
of URL (in GET mode). This URL may be intercepted by an
adversary and be changed, thus server receiving unexpected
input.
http://www.wiu.edu/users/mfbg/submit?user=‘binto’&operation=‘v
iewaccount’
An adversary can intercept this and change the operation into,
say, “changepassword”, or much worse, something invalid. This
confuses the server and the server may shutdown.
4. Time-Of-Check To Time-Of-Use (TOCTTOU)
Also known as “race condition” errors
A race condition attack happens when a
computing system that’s designed to
handle tasks in a specific sequence is forced
to perform two or more operations
simultaneously.
This technique takes advantage of a time
gap between the moment a service is
initiated and the moment a security control
takes effect.
5. Cont…
This attack, which depends on multithreaded
applications, can be delivered in one of two ways:
interference caused by untrusted processes
(essentially a piece of code that slips into a
sequence between steps of a secure programs),
and interference caused by a trusted process,
which may have the "same'' privileges.
Without proper controls, different processes can
interfere with each other.
