[Write-up] DOM XSS Using Web Messages and JSON.parse.
Disclaimer:
The techniques described in this document are intended solely for ethical use and educational purposes. Unauthorized use of these methods outside approved environments is strictly prohibited, as it is illegal, unethical, and may lead to severe consequences.It is crucial to act responsibly, comply with all applicable laws, and adhere to established ethical guidelines. Any activity that exploits security vulnerabilities or compromises the safety, privacy, or integrity of others is strictly forbidden.
This vulnerability involves DOM-based Cross-Site Scripting (DOM XSS) that occurs when a web page uses the postMessage API to receive data from another window (such as an iframe or popup), and parses the message using JSON.parse() without properly validating the source of the message or its content.
In this specific lab, the web page listens for incoming messages and directly…