SID 2253

Msg

"SMTP XEXCH50 overflow attempt"

Summary

This event is generated when an attempt is made to exploit a known vulnerability in Microsoft Exchange Server.

Classtype

attempted-admin

Impact

Serious. Possible execution of arbitrary code and Denial of Service

(DoS).

Detailed Information

A vulnerability exists in versions of Microsoft Exchange Server such that it is possible for an attacker to execute arbitrary code or cause a DoS condition on the server without the need for prior authentication as a valid user.

It is possible for an attacker to connect to the Exchange server on port 25 and send an extended verb request to the server that will cause a large amount of memory to be allocated. In Exchange Server 5.5 this may cause a DoS, whilst in Exchange Server 2000 this same condition could present the attacker with an opportunity to execute arbitrary code.

Affected Systems

  • MIcrosoft Exchange Server 5.5
  • Microsoft Exchange Server 2000

Attack Scenarios

The attacker can connect to port 25 of the server and send a specially crafted verb request.

Ease Of Attack

Simple.

False Positives

None known.

False Negatives

None known.

Corrective Action

Upgrade to the latest non-affected version of the software.

Apply the appropriate vendor supplied patches.

Contributors

  • Sourcefire Vulnerability Research Team
  • Brian Caswell
  • Nigel Houghton