What Is Grey Box Penetration Testing? Disclosed
Hi readers, this informative article discusses what is grey box penetration testing with real life example. It also discloses the working process of grey box pentesting and how it is helpful in cybersecurity.
This week was interesting. Got assigned to a grey box pentest for a logistics platform. Unlike a black box pentest, I had some access. but not full admin-level or source code. So, it was kind of in-between – some help but still had to dig a lot.
Discover More: Understand What Is White Box Pentesting
What is Grey Box Penetration Testing Exactly?
It’s the kind of test where you get partial access – maybe user creds, maybe network arch diagram, maybe just a staging env. this time they gave me a user login, API schema doc, and test env with limited logs. not full insider, not outsider either.
Early Recon: Mixed Bag
Did normal recon like dirbusting and nmap but also logged in to see what user sees. Found few endpoints not visible from web UI but mentioned in the API doc (love when devs forget to auth check those).
Internal DNS leaked a test domain that was still active. accessed it and boom – dev login panel with no captcha.
Auth Bypass and Logic Flaws
The main fun was with auth flow. they used JWTs but forgot to sign them properly. Alg was set to “none” in dev env, so I just crafted fake tokens and got access to premium features.
Also tested order submission logic — turns out you can replay the same request with a diff user_id and it assigns orders to other people. Zero validation. Scary stuff.
Some stuff I Learnt (and Re-learnt)
- Grey box penetration testing is best of both worlds. You get context, but still need to attack smart.
- Dev/test envs are goldmine. always check them.
- If an API doc exists, it’s a map. follow it.
- Logic flaws are harder to find than vulns. think like an abuser, not a scanner.
Honestly, this type of test feels closest to real-life attacks. Attacker might have creds from a leak or social engg, but not everything. So, it’s messy, incomplete but very real.
Ok, enough ranting. Hope this helps someone out there getting into DFIR or pentest. log your steps, break stuff, learn hard.