Cross-site scripting (XSS) has been a popular finding for me in 2021, discovering five XSS vulnerabilities that have been assigned CVEs. Additionally, it’s been present on recent application testing as well, so I thought it would be beneficial to cover XSS in more depth.
This video is the first in a series of blog posts that will describe various cross-site scripting attacks, remediations, and specific areas to look out for that I have seen overlooked in the sanitization of user-supplied data. This video covers the basics of cross-site scripting, including reflected, stored, and DOM-based XSS. Additionally, I’ll discuss remediation to protect against these attacks. Future videos will cover filter evasion and side-loading payloads, as well as cookie theft and advanced payloads.
I hope this video and the ones that follow give you a better idea about how cross-site scripting works, why it’s dangerous, and how to prevent it from happening to your company.