The SMTP component in Microsoft Windows 2000 SP4, XP SP2 and SP3, Server 2003 SP2, and Server 2008 Gold, SP2, and R2, and Exchange Server 2000 SP3, does not properly allocate memory for SMTP command replies, which allows remote attackers to read fragments of e-mail messages by sending a series of invalid commands and then sending a STARTTLS command, aka "SMTP Memory Allocation Vulnerability."