Are you passionate about offensive cybersecurity and looking for an opportunity to take your pentesting skills to the next level?

At ONE, we are looking for a Junior Pentester with at least 2 years of hands-on experience in web application penetration testing to join our team in a 100% remote position.

We are looking for someone with a curious and proactive mindset, a passion for ethical hacking, and a strong interest in continuously learning and exploring new attack techniques.

Key Requirements

- Web Application Pentesting: At least 2 years of hands-on experience performing penetration tests on web applications, identifying and validating security vulnerabilities.
- Pentesting Methodologies: Experience applying recognized penetration testing methodologies and standards, such as OWASP Testing Guide, OWASP Top 10, PTES or similar.
- Linux: Good command of Linux environments, including command-line tools, scripting fundamentals, and basic system administration knowledge.
- Web Security: Solid understanding of common web vulnerabilities, such as SQL Injection, XSS, CSRF, SSRF, authentication and authorization flaws, and other OWASP Top 10 risks.
- Pentesting Tools: Practical experience with tools such as Burp Suite, Nmap, Metasploit, Nikto, ffuf, Gobuster or similar.
- Networking Fundamentals: Good understanding of TCP/IP, HTTP/HTTPS, DNS and other common network protocols.
- Scripting or automation skills using Python, Bash or similar languages.
- Reporting: Ability to document technical findings, assess their impact, and provide clear remediation recommendations.

Nice to Have
- Experience performing infrastructure and network penetration testing, including vulnerability assessment of internal and external systems.




- Knowledge of Windows environments, Active Directory and common infrastructure vulnerabilities.
- Cybersecurity certifications such as eJPT, PNPT, OSCP or similar.

Main responsabilities

1. Web Application Penetration Testing

- Perform security assessments and penetration tests on web applications to identify and validate vulnerabilities.
- Analyze authentication mechanisms, access controls, session management and other application security components.
- Assess vulnerabilities based on their technical impact and potential business risk.

2. Infrastructure Security Assessments

- Support infrastructure and network penetration testing activities, including vulnerability identification and validation.
- Collaborate with senior team members on more complex security assessments.

3. Vulnerability Analysis and Research

- Research emerging vulnerabilities, attack techniques and offensive security tools.
- Develop and adapt testing techniques to identify potential security weaknesses.
- Contribute to the continuous improvement of internal testing methodologies and tools.

4. Documentation and Reporting

- Prepare clear and structured technical reports detailing identified vulnerabilities, exploitation evidence, risk levels and remediation recommendations.
- Communicate findings to internal teams and clients, providing practical guidance to improve their security posture.
- Collaborate with other cybersecurity professionals to ensure the quality and consistency of security assessments.

What We Offer What makes us different from other companies?

- Exciting professional cybersecurity projects for the largest corporations across the globe.
- 100% remote.
- A top team of highly recognized professionals in the field.
- An attractive salary.

📌 Junior Pentester (España)
🏢 One Esecurity
📍 España