Microsoft Exchange Server 2000 Command Processing Bug Lets Remote Users Cause the SMTP Service to Crash
SecurityTracker Alert ID: 1003688|
SecurityTracker URL: http://securitytracker.com/id/1003688
(Links to External Site)
Date: Feb 28 2002
Denial of service via network|
Fix Available: Yes Vendor Confirmed: Yes |
Microsoft issued a security bulletin (MS02-12) warning of a denial of service vulnerabiltiy in the Exchange 2000 mail server. A remote user can cause the SMTP service to crash.|
It is reported that the Windows SMTP service (which is used by Exchange 2000) contains a flaw in the processing of a specific SMTP command used to transfer incoming mail data. A remote user could send a malformed version of this command to cause the SMTP service to fail.
Microsoft reports that Exchange 5.5, even if installed on a Windows 2000 server, is not affected by the vulnerability.
Microsoft has assigned this vulnerability a maximum severity rating of "Low".
A remote user can cause the Exchange 2000 SMTP service to crash.|
The vendor has released a fix.|
For Windows 2000 Server, Professional and Advanced Server:
Microsoft reports that the Windows 2000 patch can be installed on systems running Windows 2000 SP2.
The fix for this issue will reportedly be included in Windows 2000 SP3.
Vendor URL: www.microsoft.com/technet/security/bulletin/MS02-012.asp (Links to External Site)
Exception handling error|
|Underlying OS: Windows (2000)|
Source Message Contents
Subject: Alert:Microsoft Security Bulletin - MS02-012|
Malformed Data Transfer Request can Cause Windows SMTP Service to Fail
Originally posted: February 27, 2002
Impact of vulnerability:Denial of Service
Maximum Severity Rating:Low
Recommendation:Customers who need the Windows 2000 SMTP services should apply the patch; all others should disable the SMTP service.
- Microsoft Windows 2000
- Microsoft Windows XP Professional
- Microsoft Exchange 2000
An SMTP service installs by default as part of Windows 2000 server products. Exchange 2000, which can only be installed on Windows
2000, uses the native Windows 2000 SMTP service rather than providing its own. In addition, Windows 2000 and Windows XP workstation
products provide an SMTP service that is not installed by default. All of these implementations contain a flaw that could enable
denial of service attacks to be mounted against the service.
The flaw involves how the service handles a particular type of SMTP command used to transfer the data that constitutes an incoming
mail. By sending a malformed version of this command, an attacker could cause the SMTP service to fail. This would have the effect
of disrupting mail services on the affected system, but would not cause the operating system itself to fail.
- Windows XP Home Edition does not provide an SMTP service, and is not affected by the vulnerability.
- Windows 2000 Professional and Windows XP Professional do provide an SMTP service, but it is not installed by default.
- Windows 2000 server products do install the SMTP service by default. However, best practices recommend disabling any unneeded services,
and systems on which the SMTP service had been disabled would not be at risk.
- Exchange 5.5, even if installed on a Windows 2000 server, is not affected by the vulnerability.
- The result of an attack would be limited to disrupting the SMTP service and, depending on the system configuration, potentially
IIS and other internet services as well. However, it would not disrupt any other system functions.
- The vulnerability would not enable an attacker to gain any privileges on the affected system or to access users' email or data.
Vulnerability identifier: CAN-2002-0055
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