Microsoft Windows Contact File HTML Injection Mailto Link Arbitrary Code Execution
This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Microsoft Windows. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The flaw is due to the processing of ".contact" files, the E-mail address field takes an expected E-mail address value, however the .CONTACT file is vulnerable to HTML injection as no validation is performed. Therefore, if an attacker references an executable file using an HREF tag it will run that instead without warning instead of performing the expected email behavior. This is dangerous and would be unexpected to an end user. The E-mail addresses Mailto: will point to an arbitrary executable like. <a href="calc.exe">pwn@microsoft.com</a> Additionally the executable file can live in a sub-directory and be referenced like "<a href="mydirmalicious.exe">pwn@microsoft.com</a>" or attackers can use directory traversal techniques to point to a malware say sitting in the targets Downloads directory like: <a href="........UsersvictimDownloadsevil.exe">pwn@microsoft.com</a> Making matters worse is if the the files are compressed then downloaded "mark of the web" (MOTW) may potentially not work as expected using certain archive utils.
