# Vulnerability type: Server Side Request Forgery # Vendor: https://www.k2.com/ # Product: K2 Smartforms # Affected version: 4.6.11 # Credit: Foo Jong Meng # CVE ID: CVE-2018-9920 # DESCRIPTION: Server side request forgery exists in the runtime application in K2 smartforms 4.6.11 via a modified hostname in an https://*/Identity/STS/Forms/Scripts URL. By replacing the "GET" parameter to any external domain (i.e. https://www.external-domain.com) while accessing the affected application (e.g. https://url/Identity/STS/Forms/Scripts). The resulting page shows URL with https://url/Identity/STS/Forms/Scripts but rendering https://www.external-domain.com in the body (aka local web defacement). A port scan on the internal servers can be performed by changing the "GET" parameter URL and analysing the results of the return page. # PROOF OF CONCEPT: 1. Use a web proxy (i.e zapproxy, burp) to intercept "GET" request for: https://url/Identity/STS/Forms/Scripts 2. Replace the "GET" parameter to any external domain (i.e. https://www.external-domain.com/) 3. The resulting page is one with https://url/Identity/STS/Forms/Scripts but showing https://www.external-domain.com/ in the body.
