CVE-2026-40487: Arbitrary File Upload > Stored XSS > Account Takeover in Postiz
After obtaining my OSWE, I started appreciating white box analysis much more. So every now and then I pick an open-source project I like, analyze the source code, try to understand how it works, and when I come across critical functions I ask myself: “what if this didn’t work as expected?”. Today I’ll tell you how I discovered this Arbitrary File Upload via MIME-type spoofing that led to a Stored XSS in Postiz, an open-source social media management tool with over 600 instances exposed on the internet. The vulnerability allows an attacker to act as the victim: steal API keys, exfiltrate tokens from all connected social integrations (Instagram, X, LinkedIn, Facebook, TikTok and 23 other providers), publish and delete posts on their behalf, and create persistent OAuth backdoors that survive password changes. ...
OSWE: White-Box Hacking
The OffSec Web Expert (OSWE) exam is known for its white-box methodology. You don’t simply “scan” a webapp to find potential vulnerabilities, you read the code, understand it, and find the flaws to forge the perfect exploit. Nothing out of reach with the right technical preparation and experience. AWAE/OSWE/WEB-300 Let’s first clarify what we’re talking about. OSWE (Offensive Security Web Expert) is the certification, while AWAE (Advanced Web Attacks and Exploitation, also known as WEB-300) is the course that prepares you for the exam. ...
Bug Hunting NASA
It doesn’t happen every day that you receive a letter of recognition from NASA - National Aeronautics and Space Administration, but it actually happened. I received an official acknowledgment for finding and reporting vulnerabilities in their systems. How It All Started While browsing the web, I decided to analyze some of NASA’s public servers. Among them, I found some that were vulnerable, so I decided to report my findings to their security team, following their responsible disclosure policy. ...
Featured in HackerJournal Issue #275
HackerJournal holds a special place in my heart. It’s one of the first hacking magazines I read as a kid, diving into its pages to fuel my passion for hacking and technology. For enthusiasts, it was a real gateway into the world of ethical hacking and cybersecurity. The Article: “I Know Where You Post From” Specifically, the article I worked on in collaboration with Unlock Security, titled “So da dove posti” (I Know Where You Post From), appears on page 36. It details the process I followed to geolocate an individual using only open source intelligence (OSINT) techniques, starting from a single public photo. ...
OSINT Challenge
Inspired by the numerous challenges from Gary Ruddell, Unlock Security introduced a very fun OSINT challenge that I managed to solve: no contextual information, just a single blurry photo with few visible details. 🔎 The Challenge: Can you determine the location where this photo was taken? Step 1: Using Facial Recognition To begin, I used facecheck.id, an online facial recognition tool, to check if the person in the photo appears on any public platform or social media. ...
OSCP Cheatsheets
Preparing for OffSec’s OSCP exam is a complex challenge that requires both technical skills and mental organization. During my preparation, I realized how difficult it was to remember every command and syntax. That’s why I created a structured note-taking system to quickly retrieve information, making my workflow more efficient. I collected everything on GitBook, creating a practical guide to tackle the OSCP in a more organized and effective way. 👉 Check out my GitBook ...
CVE-2022-44023
PwnDoc up to version 0.5.3 allows remote attackers to identify disabled account usernames by exploiting response messages during authentication attempts. Product CVE CVSSv3 Score CWE PwnDoc CVE-2022-44023 5.3 (Medium) CWE-307 Exploitation Steps This vulnerability allows username enumeration of disabled accounts in PwnDoc (tested on version 0.5.3 - 2022-07-19) by observing server responses to login attempts. Example Scenario: Suppose the following users were registered and subsequently disabled in PwnDoc: ...
CVE-2022-44022
PwnDoc up to version 0.5.3 allows remote attackers to identify valid usernames by exploiting response timings during authentication attempts. Product CVE CVSSv3 Score CWE PwnDoc CVE-2022-44022 5.3 (Medium) CWE-307 Exploitation Steps This vulnerability allows username enumeration in PwnDoc (tested on version 0.5.3 - 2022-07-19 and earlier) by observing web server response timings during login attempts. Example Scenario: Suppose the following users are registered in PwnDoc: ...
CVE-2020-13654 - My First CVE: XSS > CSRF > Privesc to ADMIN
Finding your first CVE is one of those things that stays with you. Not so much for the assigned number, which is ultimately just an identifier in a database, but for the process: the moment you realize the bug is real, that nobody has reported it before you, and that you have the responsibility to handle it correctly. I’m telling this story in this post from start to finish: the discovery, the exploit, and finally the responsible disclosure process with MITRE. ...
About me
Hi, I’m Lorenzo :) I work in cybersecurity, with a focus on web hacking. In this space I’ll share my experiences in this field, my projects, and the small milestones I’ve achieved.