Chevereto Image Upload Script is prone to a cross-site scripting vulnerability and an information-disclosure vulnerability because it fails to properly sanitize user-supplied input before using it in dynamically generated content.
An attacker may leverage the cross-site scripting issue to execute arbitrary script code in the browser of an unsuspecting user in the context of the affected site. This can allow the attacker to steal cookie-based authentication credentials and to launch other attacks.
An attacker may leverage the information-disclosure issue to enumerate the existence of local files. Information obtained may aid in further attacks.
Chevereto Image Upload Script 1.91 is vulnerable; other versions may also be affected.