This tweet discusses the improvements in Vercel WAF (Web Application Firewall) in protecting against a Remote Code Execution (RCE) vulnerability known as react2shell. The user wonders if Vercel's WAF has become stronger, particularly in dealing with bypass techniques involving constructor blocking. The mention of 'constructor blocking' refers to a specific method attackers might use to bypass WAF protections by exploiting JavaScript constructors to execute malicious code. The tweet also hints at other technical aspects like HTTP parser differentials that could play a role in bypassing WAF rules. Overall, it suggests that Vercel's WAF has been enhanced to better defend against sophisticated bypass attempts related to the react2shell vulnerability, but some nuanced bypass techniques such as constructor blocking may still be under discussion or investigation.
For more insights, check out the original tweet here: https://twitter.com/S1r1u5_/status/1997564541169967361. And don’t forget to follow @S1r1u5_ for more exciting updates in the world of cybersecurity.