// Research, Writeups & CVE Advisories

SECURITY
RESEARCH

Vulnerability research, exploit writeups, red team methodologies, certification journeys, and CVE advisories by Brendon Teo.

CVE Research

CVE-2024-40125: File Upload → Full Admin RCE

How an unvalidated PHP file upload in CLESS Server v4.5.2's Media Manager became a CRITICAL 9.8 unauthenticated RCE granting full Windows administrative access.

Web VAPT

OAuth 2.0 Misconfigurations & API Attack Chains

Real-world OAuth flaws from live engagements — open redirects, token leakage, PKCE bypass, and chaining SSRF to internal service exploitation.

Infra VAPT

Automating Infra VA: From Nessus to Client Report

How I built CIS-NessusToExcel to automate the most painful part of infrastructure assessments — generating clean, consistent reports from raw Nessus data.

Certifications

OSEP, OSWE & CRTO — The Advanced Cert Path

Lessons from the advanced offensive security certification grind — what separates OSEP from OSCP, and how CRTO fills the real-world red team gap.