The Mono XSP ASP.NET server allows for source code disclosure when a %20 is appended to a URI. Version 1.2.1 is affected.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/53189/monoxsp.txt
Source: https://packetstormsecurity.com/files/53189/monoxsp.txt.html