This tweet describes a complex vulnerability chain found during a bug bounty program that involves multiple steps of attacks. It starts with Client-Side Template Injection (CSTI), which is a type of vulnerability where an attacker can inject template directives that execute in the client application. This initial injection leads to an XSS gadget combined with a Web Application Firewall (WAF) bypass, allowing the attacker to execute cross-site scripting despite WAF protections. After successfully bypassing the WAF and triggering XSS, the attacker then exploits a Content Security Policy (CSP) bypass. CSP is a security mechanism to prevent certain types of attacks like XSS, and bypassing it means the attacker can load or execute unauthorized scripts. Following the CSP bypass, the attacker uses fetch requests to interact with backend services or APIs, furthering their control. Finally, this chain culminates in cookie hijacking, where the attacker steals session cookies to impersonate the victim or gain unauthorized access. The tweet underscores the complexity and impact of security vulnerabilities when chained together, especially focusing on bypassing layered security like WAF and CSP to hijack cookies.
Check out the original tweet here: https://twitter.com/__the7th/status/2033801340049052133