Getting P1 Bug Only With My Cellphone

Hi everyone, how are you? I hope you guys are well. I'm RyuuKhagetsu, this is my article in English, sorry if there are any mistakes. I hope you enjoy my article. Let's call the target website "site.com".

This story demonstrates how mobile devices can be powerful tools for bug hunting, proving that you don't always need expensive equipment or complex setups to discover critical vulnerabilities.

The Mobile Bug Hunting Journey Begins

It all started when my friend asked me to play a private game. Before registering an account, I decided to try finding some security holes on the website through my phone. This decision would lead to discovering a critical P1 (Priority 1) vulnerability.

Mobile bug hunting has several advantages:

• Accessibility: You can test websites anywhere, anytime
• Realistic User Experience: Testing from a mobile perspective often reveals unique vulnerabilities
• Different Attack Surface: Mobile interfaces sometimes have different validation logic
• Convenience: No need for complex setup or heavy equipment

Initial Vulnerability Discovery

On the login form, I started testing for common vulnerabilities. I began with basic input validation tests to see if there were any security flaws.

First, I tested with legitimate credentials:

The website displayed a normal error message:

SQL Injection Discovery

Then I decided to test for SQL injection by adding a single quote (') to the username field:

This time, I got a different response:

I got excited because this was a clear sign of SQL Injection vulnerability. The different error message indicated that the application was not properly sanitizing user input before including it in SQL queries.

Mobile Traffic Interception

I immediately opened SandroProxy to capture the HTTP request data. SandroProxy is a powerful mobile proxy tool that allows you to intercept and analyze network traffic directly from your Android device.

SandroProxy Setup Process:

1. Install SandroProxy on Android device
2. Configure proxy settings in device Wi-Fi configuration
3. Start proxy server within the app
4. Capture HTTP/HTTPS traffic in real-time

The captured request data showed the vulnerable parameter and how the application was processing the input. This data would be crucial for further exploitation using automated tools.

Advanced Exploitation with Termux

I copied all the request data from SandroProxy and created an in.txt file in Termux, then pasted the captured request there. Termux is a powerful terminal emulator for Android that allows you to run Linux tools directly on your mobile device.

Termux Setup for SQL Injection Testing:

I then ran SQLMap with the captured request file:

SQLMap Parameters Explanation:

• -r in.txt: Use request from file
• --level 5: Maximum test level (most comprehensive)
• --risk 3: Maximum risk level (most aggressive)
• --dbs: Enumerate database names

Successful Database Enumeration

After waiting for a while, I successfully obtained the database names from the website. SQLMap confirmed the SQL injection vulnerability and was able to extract sensitive information about the database structure.

I didn't continue the exploitation further because it would be against responsible disclosure rules. At this point, I had sufficient proof of the vulnerability's severity and immediately prepared to report it to the website administrators.

Impact Assessment

The discovered SQL injection vulnerability had severe security implications:

• Data Breach Risk: Potential access to all user data in the database
• Authentication Bypass: Possible login without valid credentials
• Data Manipulation: Ability to modify or delete database records
• System Compromise: Potential for further privilege escalation
• P1 Severity: Critical impact on security and business operations

Responsible Disclosure Timeline

I immediately reported the vulnerability following responsible disclosure practices:

The developer gave me permission to disclose this report without mentioning their specific identity, allowing me to share this educational content while respecting their privacy.

Mobile Bug Hunting Lessons

This experience taught me several valuable lessons about mobile bug hunting:

Technical Lessons:

• Mobile Tools Are Powerful: SandroProxy + Termux + SQLMap created a complete testing environment
• Error Messages Reveal Vulnerabilities: Different error responses often indicate security flaws
• Simple Tests Find Critical Bugs: Basic SQL injection testing discovered a P1 vulnerability
• Mobile Perspective Matters: Testing mobile interfaces can reveal unique vulnerabilities

Process Lessons:

• Document Everything: Capture requests and responses for proper reporting
• Know When to Stop: Ethical boundaries are crucial in security research
• Report Responsibly: Follow proper disclosure procedures
• Mobile-First Approach: Don't underestimate mobile testing capabilities

Mobile Bug Hunting Toolkit

For aspiring mobile bug hunters, here's the essential toolkit used in this discovery:

Required Android Apps:

• SandroProxy: HTTP/HTTPS traffic interception
• Termux: Linux terminal environment
• Text Editor: For creating request files
• Web Browser: For initial testing and validation

Command Line Tools (via Termux):

• SQLMap: Automated SQL injection testing
• Python: For running various security tools
• Git: For cloning security tools repositories
• Curl/Wget: For manual HTTP requests

Security Recommendations

To prevent SQL injection vulnerabilities like this one, developers should implement:

• Parameterized Queries: Use prepared statements for all database interactions
• Input Validation: Validate and sanitize all user inputs
• Error Handling: Implement generic error messages that don't reveal system information
• Least Privilege: Database users should have minimal necessary permissions
• Security Testing: Regular penetration testing and code reviews
• WAF Implementation: Web Application Firewalls can help detect and block SQL injection attempts

Conclusion

This experience proves that effective bug hunting doesn't always require expensive equipment or complex setups. With just a smartphone, the right apps, and proper methodology, security researchers can discover critical vulnerabilities that have significant impact.

The key takeaways from this mobile bug hunting success story are:

• Simple tools can lead to major discoveries
• Mobile testing provides unique perspectives
• Systematic approach yields better results
• Responsible disclosure benefits everyone

Maybe that's all from me, hopefully it can be a reference for you and sorry if there are things that are not clear. I'm RyuuKhagetsu, see you in next article.