Buffer overflow in Microsoft MSN Chat ActiveX Control, as used in MSN Messenger 4.5 and 4.6, and Exchange Instant Messenger 4.5 and 4.6, allows remote attackers to execute arbitrary code via a long ResDLL parameter in the MSNChat OCX.

Microsoft MSN Messenger allows remote attackers to cause a denial of service via a plaintext message containing the ".pif" string, which is interpreted as a malicious file extension and causes users to be kicked from a group conversation. NOTE: it has been reported that Gaim is also affected, so this may be an issue in the protocol or MSN servers.