Foxit Reader Facebook Plugin is prone to a flaw in the way it loads dynamic-link libraries (DLL). The Facebook plug-in (facebook_plugin.fpi) uses a fixed path to look for specific files or libraries (e.g. dwmapi.dll). This path includes directories that may not be trusted or under user control. By placing a custom version of the file or library in the path, the program will load it before the legitimate version. This allows a local attacker to inject custom code that will be run with the privilege of the program or user executing the program.
This attack can be leveraged remotely in some cases by placing the malicious file or library on a network share or extracted archive downloaded from a remote source. This can be done by tricking a user into opening a PDF file from the local file system or a USB drive in some cases. This attack scenario is certainly possible, but rare.
Loss of Integrity
It has been reported that this issue has been fixed. Upgrade to version 5.4, or higher, to address this vulnerability.