source: https://www.securityfocus.com/bid/8977/info

It has been reported that Easy PHP Photo Album is prone to a HTML injection vulnerability that may allow an attacker to execute HTML code in a user's browser. The issue is reported to be present in the 'dir' parameter. This problem is due to insufficient sanitization of user-supplied input.

Successful exploitation of this vulnerability may allow an attacker to steal cookie-based authentication credentials. Other attacks are also possible.

Easy PHP Photo Album version 1.0 has been reported to be vulnerable to this issue, however prior versions may be affected as well.

http://www.example.com/photos/showimages.php?dir=<iframe%20src="C:\"%20width=400%20height=400></iframe>
http://www.example.com//photos/showfullimage.php?dir=[dir name][spc]St[spc]Clair&image=<h1>hello</h1>