GEN:SID 1:658
Message SMTP exchange mime DOS
Summary This event is generated when a denial of service is attempted on a Microsoft Exchange mail server.
Impact Denial of service.  This will cause the Exchange server to fail.  
Detailed Information A vulnerability exists in Microsoft Exchange 5.5 that causes a denial of service if a MIME header contains the string 'charset = ""'.  The Exchange server does not properly handle this MIME header string, causing it to crash.
Affected Systems Microsoft Exchange server 5.5
Attack Scenarios An attacker can supply a malicious string in the MIME header causing the Exchange server to fail.
Ease of Attack Easy.  An attacker can telnet to port 25 of the Exchange server, start a dialogue with the server, and supply the malicious string in the MIME header.
Corrective Action Apply the appropriate patch or upgrade to Exchange 5.5 service Pack 4.
Additional References Microsoft:
http://www.microsoft.com/technet/treeview/default.asp?url=/technet/security/bulletin/ms00-082.asp

Miscellaneous:
http://packetstormsecurity.nl/0011-exploits/exchange.dos.txt

Rule References nessus: 10558
cve: 2000-1006
bugtraq: 1869
url: www.microsoft.com/technet/security/bulletin/MS00-082.mspx