CRLFuzz in Termux – Scan for CRLF Injection Vulnerabilities

CRLFuzz is a fast and lightweight command-line tool used to detect CRLF (Carriage Return Line Feed) injection vulnerabilities in web applications. It helps security researchers and developers test target URLs for HTTP response splitting issues using different request options and payloads. You can easily install and use CRLFuzz in Termux with a few simple commands.

Here’s what you can do with CRLFuzz in Termux:

Scan a single URL for CRLF injection.
Scan multiple URLs from a file.
Use custom HTTP methods.
Send custom headers and request data.
Save scan results to a file.
Use proxy support.
Perform fast concurrent scanning.

Install CRLFuzz in Termux

Below are the simple commands to install CRLFuzz in Termux. Copy and run each command one by one to install the tool.

Update Termux packages.

pkg update && pkg upgrade -y

pkg update && pkg upgrade -y

Install the required packages.

pkg install git golang -y

pkg install git golang -y

Clone the CRLFuzz repository.

git clone https://github.com/dwisiswant0/crlfuzz

git clone https://github.com/dwisiswant0/crlfuzz

Move into the project directory.

cd crlfuzz/cmd/crlfuzz

cd crlfuzz/cmd/crlfuzz

Build the tool.

go build

go build

Move the binary to the Termux binary directory.

mv crlfuzz $PREFIX/bin/crlfuzz

mv crlfuzz $PREFIX/bin/crlfuzz

CRLFuzz is now installed and ready to use.

Use CRLFuzz in Termux

After installing CRLFuzz, you can use different commands to scan target URLs for CRLF injection vulnerabilities and customize your requests.

Display the help menu.

crlfuzz -h

crlfuzz -h

Scan a single URL.

crlfuzz -u https://example.com

crlfuzz -u https://example.com

Scan URLs from a file.

crlfuzz -l urls.txt

crlfuzz -l urls.txt

Specify an HTTP request method.

crlfuzz -u https://example.com -X POST

crlfuzz -u https://example.com -X POST

Send request data.

crlfuzz -u https://example.com -d "id=1"

crlfuzz -u https://example.com -d "id=1"

Use a custom header.

crlfuzz -u https://example.com -H "User-Agent: Mozilla/5.0"

crlfuzz -u https://example.com -H "User-Agent: Mozilla/5.0"

Use a proxy.

crlfuzz -u https://example.com -x http://127.0.0.1:8080

crlfuzz -u https://example.com -x http://127.0.0.1:8080

Save scan results to a file.

crlfuzz -l urls.txt -o results.txt

crlfuzz -l urls.txt -o results.txt

Set the concurrency level.

crlfuzz -l urls.txt -c 50

crlfuzz -l urls.txt -c 50

Enable silent mode.

crlfuzz -l urls.txt -s

crlfuzz -l urls.txt -s

Enable verbose mode.

crlfuzz -l urls.txt -v

crlfuzz -l urls.txt -v

Display the installed version.

crlfuzz -V

crlfuzz -V

Run the command you need, and CRLFuzz will start scanning the target and show the results.

Understanding the Results

After the scan starts, CRLFuzz will test the target website using different methods and show the results in the terminal.

[ERR] means the test was not successful or the website rejected the request.
If the tool finds a possible CRLF injection vulnerability, it will display a positive result.
If you only see [ERR] messages, it usually means the tool did not find a vulnerability on the target website.

End Note

CRLFuzz is a simple and fast security tool for detecting CRLF injection vulnerabilities in web applications. It is useful for learning web security and performing authorized security testing from the Termux terminal.