SMTP service in (1) Microsoft Windows 2000 and (2) Internet Mail Connector (IMC) in Exchange Server 5.5 does not properly handle responses to NTLM authentication, which allows remote attackers to perform mail relaying via an SMTP AUTH command using null session credentials.
A capture-replay flaw exists when the design of the product makes it possible for a malicious user to sniff network traffic and bypass authentication by replaying it to the server in question to the same effect as the original message (or with minor changes).
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Exchange_server | Microsoft | 5.5 (including) | 5.5 (including) |
| Exchange_server | Microsoft | 5.5-sp1 (including) | 5.5-sp1 (including) |
| Exchange_server | Microsoft | 5.5-sp2 (including) | 5.5-sp2 (including) |
| Exchange_server | Microsoft | 5.5-sp3 (including) | 5.5-sp3 (including) |
| Exchange_server | Microsoft | 5.5-sp4 (including) | 5.5-sp4 (including) |