About Me
Hi, I'm passionate about cybersecurity, particularly penetration testing. I specialize in testing websites, APIs, and AI-powered applications, and occasionally mobile applications. I also actively participate in bug bounty programs on platforms like Bugcrowd, HackerOne, and YesWeHack. Notably, I'm ranked as the 5th top hacker in Pinterest's Hall of Fame π and have successfully discovered vulnerabilities in Googleβs chat and AI-integrated applications, earning recognition and swag from Google π.
My expertise lies in Broken Access Control vulnerabilities (they keep me up at night π), with additional experience in identifying Business Logic Errorsβincluding those introduced by LLM and agent-based workflows. I have hands-on experience assessing Agentic AI applications, covering areas such as prompt injection and indirect prompt injection, tool abuse, unsafe agent actions, OAuth and token exposure, and AI-driven business logic flaws.
With a background as a Backend Engineer π», I have a deep understanding of how modern systems operateβfrom traditional APIs to AI orchestration layersβwhich significantly enhances my ability to identify complex and non-obvious vulnerabilities. Basically, I break things for a livingβ¦ but only in the most ethical way possible ππ₯.
Services
Agentic AI Application Security
Security assessment of AI-powered and agent-based applications to identify risks such as prompt injection, unauthorized actions, data leakage, and unsafe tool orchestration.
- Prompt Injection & Indirect Prompt Injection Testing
- Agent Tool Abuse & Unauthorized Action Analysis
- LLM Output Manipulation & Trust Boundary Testing
- AI Workflow & Agent-to-Agent Communication Review
- OAuth, API, and Token Exposure in AI Integrations
- Business Logic Flaws in AI Decision-Making
Web Application Security
Comprehensive security assessment of web applications to identify vulnerabilities and potential threats.
- OWASP Top 10 Vulnerability Assessment
- API Security Testing
- Authentication & Authorization Testing
- Business Logic Testing
- Security Headers Analysis
Mobile Application Security
In-depth security analysis of mobile applications for both iOS and Android platforms.
- Static & Dynamic Analysis
- Data Storage Security
- Network Communication Security
- Reverse Engineering
- Code Review & Analysis
API Security Assessment
Specialized security testing for APIs and microservices to ensure robust protection.
- REST API Security Testing
- GraphQL Security Assessment
- API Authentication Testing
- Rate Limiting Analysis
- Data Validation Testing
π Interested in securing your applications? Let's discuss how I can help protect your digital assets.
Contact MeDisclosed Reports
Attacker Can Make Other Pinner's Idea Pin Can't Be Commented And The Analytics On Idea Pin Page Can't Be Seen By The Owner
Program: Pinterest
An attacker can trigger an issue by reacting to an Idea Pin with an invalid reaction_type (number 10). This causes the UI for comments and analytics to disappear, preventing the owner from interacting with their own Idea Pin. The vulnerability arises due to the API accepting unsupported reaction types.
Read MoreWriteups
Indirect Prompt Injection: Summarize Email Leads to Several Unauthorized Actions
This article highlights an indirect prompt injection issue where hidden instructions inside an email cause an AI email summarizer to perform unauthorized actions without user consent. It shows how seemingly harmless features like email summarization can be abused when AI models are allowed to act on untrusted content.
Getting Paid With Just Picking Color β Bug Bounty
I shared a bug bounty experience where I found a CSS injection issue through a simple color picker in a healthcare web app, which could break the hospital dashboard. Even though the impact was low, the report was accepted and rewarded, showing that small features can still lead to valid findings.
Research
Web Cache Deception Attack on PHP x Nginx
I explained how a Web Cache Deception (WCD) attack works on a PHP website running behind Nginx by tricking the caching proxy into storing sensitive dynamic pages (like profiles or admin dashboards) as if they were static resources, using URLs with fake file extensions (e.g., profile.php/test.css), so that an attacker can then retrieve those cached pages and access private data or even admin content without authentication β highlighting how misconfigured caches and backend behavior differences can lead to serious data exposure risks.
Bug Bounty Platforms
Awards
π₯ Pinterest Top 3rd Hacker
Recognized for discovering multiple vulnerabilities in Pinterest's platform, contributing to their bug bounty program's success. Achieved this ranking through consistent high-quality submissions.
Link: Hall of Fames
π₯ Hostinger Top 22th Hacker
Recognized for discovering multiple vulnerabilities in Hostingerβs platform, earning 22nd place in their bug bounty program through consistent, high-quality submissions.
Link: Hall of Fames
Certifications
Certified Ethical Hacker (CEH)
Professional certification demonstrating expertise in ethical hacking and penetration testing methodologies.
Valid until: August 31, 2027
Talks
ποΈ How Hackers Manipulate Data
Presented an in-depth webinar on Insecure Direct Object References (IDOR) with real-world examples and backend code walk-throughs.
Where I spoke: CyberAcademyID (Cyber Insight)
ποΈ Approaching Bug Bounty Targets
A practical guide on how to identify and approach bug bounty targets effectively, focusing on finding valuable vulnerabilities and maximizing success in bug bounty programs.
Where I spoke: CSRG
Security Tools
π LinkFinder (Chrome Extension)
Linkfinder by Rdzsp is the superhero your browser never knew it needed! π¦ΈββοΈπ¦ΈββοΈ This awesome extension collects endpoints from JavaScript files on websitesβso you don't have to. Whether you're a security researcher, a curious dev, or someone who just likes to peek behind the digital curtains, this extension has got your back! π»π
Link: linkfinder-by-rdzsp
π Dependency Confusion Checker
Python-based tool for identifying potential dependency confusion vulnerabilities in JavaScript (`package.json`) and Python (`requirements.txt`) projects.
π Prototype Pollution Checker
Prototype Pollution Checker is a security tool designed to detect potential Prototype Pollution vulnerabilities on target URLs by injecting payloads and verifying responses. This tool uses Seleniumβ¦
π See more tools on my GitHub: github.com/rdzsp
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