In 2025, a Ukrainian cybersecurity researcher became one of the region’s most successful bug hunters, earning more than $100,000 in rewards for discovered vulnerabilities.
First Steps
The story began with an interest in testing website security during his university years. His first reports were amateur efforts and focused on simple vulnerabilities such as XSS and SQL injection. Over time, the bug hunter began working with international platforms such as HackerOne and Bugcrowd.
The Turning Point
The real breakthrough came after he discovered a critical vulnerability in the API of a major fintech company. It combined BOLA (Broken Object Level Authorization) and SSRF, allowing access to confidential customer data. The company paid him a personal record reward of $20,000 for the report.
Strategy and Approach
- Focus on logic flaws — business logic vulnerabilities and chained exploits.
- Automation of routine checks using custom scanners and scripts.
- Continuous learning — participating in CTFs, reading write-ups, and experimenting with new techniques.
Recognition in the Community
His name appeared in the Hall of Fame of dozens of companies, including major technology companies. In 2025, he entered the global top 50 bug hunters on one of the platforms.
Advice for Beginners
- Start by learning the OWASP Top 10 and the API Security Top 10.
- Take notes and build your own testing checklist.
- Do not ignore “low-hanging fruit” — sometimes simple bugs bring the greatest rewards.
- Be polite and professional when communicating with companies and platforms.
His story proves that persistence, continuous improvement, and a thoughtful approach can turn an interest into a stable source of income and recognition in the international community.