Proton Mail XSS Vulnerability: A Deep Dive into the 2022 Exploit
The Sonar Research team identified the vulnerability during a routine audit of Proton's open-source repositories. The issue stemmed from how the web application handled user-controlled HTML. While senders need the ability to style messages, failing to properly sanitize certain tags can allow malicious tags to execute in a reader's browser. How the Exploit Worked Proton Exploit
Proton maintained its commitment to security through its Responsible Vulnerability Disclosure Policy . Proton Mail XSS Vulnerability: A Deep Dive into
When possible, use native desktop or mobile apps which often have different attack surfaces than web-based versions. If you'd like to refine this draft, tell me if you want to: How the Exploit Worked Proton maintained its commitment
If successful, the script would run in the victim's session, allowing the attacker to "see" what the user sees—effectively stealing the decrypted content of their inbox. Proton's Response and Resolution