The sendRequest method in HTTPClient Class in file /inc/HTTPClient.php in DokuWiki 2016-06-26a and older, when media file fetching is enabled, has no way to restrict access to private networks. This allows users to scan ports of internal networks via SSRF, such as 10.0.0.1/8, 172.16.0.0/12, and 192.168.0.0/16.

DokuWiki 2016-06-26a and older uses $SERVER[HTTPHOST] instead of the baseurl setting as part of the password-reset URL. This can lead to phishing attacks. (A remote unauthenticated attacker can change the URL's hostname via the HTTP Host header.) The vulnerability can be triggered only if the Host header is not part of the web server routing process (e.g., if several domains are served by the same web server).