Buffer overflow in Internet Mail Connector (IMC) for Microsoft Exchange Server 5.5 allows remote attackers to execute arbitrary code via an EHLO request from a system with a long name as obtained through a reverse DNS lookup, which triggers the overflow in IMC's hello response.
Buffer Copy without Checking Size of Input The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.