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# Username Enumeration via Subtly Different Responses
Username Enumeration via Subtly Different Responses notes for PortSwigger Web Security Academy labs, including exploitation workflow, payload testing, Burp Suite validation, and remediation context.
### Username Enumeration via Subtly Different Respons
The site is slightly vulnerable to the enumeration of user names as well as to the gross password force. / An account uses a username and password present in the provided wordlists. / Purpose: Find a valid user name, brute-force password, and then access the **My account** page.
#### Lab Data
* Wordlist of user names ( Authentication lab users ).
* Password Wordlist ( Authentication lab passwords ).
* Standard login form.
#### Step 1 – User Name List
1. Intercept the login form request and send it to **Intruder**.
* Run an attack on the **username** parameter using the user name wordlist.
* By default, the server returns the message:/ `Invalid username or password`.
* In **settings**dIntruder, set a condition for **do not match** this generic answer (in order to filter identical responses).
* In observing the results, we find an entry whose response differs slightly: / a response without the usual point in the message, associated with the user **alpha**.
It is deduced that **alpha** is a valid user name.
#### Step 2 – Brute Password Strength
1. Keep the same login request, with **alpha** fixed as username.
2. Configure Intruder to attack the **password** parameter, using the password wordlist.
3. Launch the attack and compare server responses.
4. For the password **123456**, the answer is a **302** marked as ok in the notes, indicating that the connection attempt was successful.
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