This vulnerability allows remote attackers to disclose sensitive information on vulnerable installations of Foxit Reader 8.3.1.21155. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within the parsing of the xTsiz member of SIZ markers. The issue results from the lack of proper validation of user-supplied data, which can result in a read past the end of an allocated object. An attacker can leverage this in conjunction with other vulnerabilities to execute code in the context of the current process. Was ZDI-CAN-5013.