The remote host is vulnerable to a script injection attack.
The remote host is running YaPiG, a web-based image gallery written in PHP. According to its banner, the version of YaPiG installed on the remote host is prone to script insertion attacks because it does not sanitize malicious EXIF data stored in image files. Using a specially-crafted image file, an attacker can exploit this flaw to cause arbitrary HTML and script code to be executed in a user's browser within the context of the affected application.
Upgrade or patch according to vendor recommendations.