This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Microsoft Office Excel. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The flaw exists within the methods used for RealTimeData Record Parsing. When handling a stTopic field has a bit set specifying double byte characters in the following field the value of a global pointer is improperly calculated. This pointer is later used in a memcpy operation whose source is user supplied data. A remote attacker can exploit this vulnerability to execute arbitrary code under the context of the user.