Segfault ethical hacking week 4

 

1. Burp Suite

Burp Suite is a web proxy tool that intermediates requests and responses between the client and the web server. By using a proxy, it allows the analysis of all transmitted packets, enables packet modification, and supports the delivery of modified packets to the server.

User > Display > Appearance 

It can be switched to dark mode.

Burp Proxy Setting

Register proxy listener

Bind to Port

Set the port that the proxy listener will use.

Bind to address

    Loopback only : Receives only requests coming from the local system.

    All interafces : Receives requests from all network interfaces.

    Specific address : Receives only requests from a designated address.

2. Burp Suite Functions

Intercept :

    Halts incoming packets. Packets intercepted can be modified and sent to the web server.

History : 

    Stores all packets observed through the proxy. Detailed inspection is possible.

Repeater : 

    Sends the same request or slightly modified requests repeatedly for response analysis.

Decoder: 

    Performs operations such as encryption, decryption, or hash transformation on extracted data from packets. 

Comparer: 

    Compares two sets of data to easily identify differences

Request: 

It contains applied resources or client information.
Looking at GET /4_burp/flag.php HTTP/1.1, it is composed of:

• Method: The action to be performed (e.g., GET).
• Path: The specific route to the resource (e.g., /4_burp/flag.php).
• Protocol: The communication protocol being used (e.g., HTTP).
• Protocol Version: The version of the protocol (e.g., 1.1).

Response: 

It contains applied resources or client information.
Looking at HTTP/1.1 200 OK, it is composed of:

• Protocol: The communication protocol being used (e.g., HTTP).
• Protocol Version: The version of the protocol (e.g., 1.1).
• Status Code: Indicates the result of the request (e.g., 200 OK).

The output value is displayed with a blank line below the header.

Status Code: 

    200 : OK

    300 : Redirect

    400 : Client Error

    500: Server Error

Burp Suite Simple Task

    Compares two sets of data to easily identify differences

Task 1.

It indicates that the User-Agent in the header should be set to Segfaultdevice. The User-Agent header identifies the client making the request, and specifying Segfaultdevice will send that identifier to the server during communication.

If I set the User-Agent in the header to Segfaultdevice, I can obtain the flag segfault{ModRequest}. 

Task 2.

Use the Comparer tool to compare two sets of data. If there are differences between them, they will be highlighted with color for easy identification.

I can find segfault and {lookEasy}. 

Task 3.

I entered numbers ranging from 1 to 20 in the Answer field

I can find segfault{RePeatAgain} 

Task 4.

Using the Decoder, I encoded "admin" instead of "user," obtaining the value %59%57%52%74%61%57%34%3d. By inputting this encoded value into the cookie field, I then analyzed the response to determine the returned value.

By decoding the value WXpKV2JscHRSakZpU0ZJM1VrZFdhbUl5VW14VmJWWjNXbGRHTUdaUlBUMD0= in Base64 three times, I could retrieve the flag mentioned below.

segfault{DecodeRepeat}