Alert: Microsoft Security Bulletin - MS03-028

From: Russ (Russ.Cooper_at_RC.ON.CA)
Date: 07/16/03

  • Next message: Russ: "Alert: Microsoft Security Bulletin - MS03-027"
    Date:         Wed, 16 Jul 2003 13:01:21 -0400
    To: NTBUGTRAQ@LISTSERV.NTBUGTRAQ.COM
    
    

    http://www.microsoft.com/technet/security/bulletin/MS03-028.asp

    Flaw in ISA Server Error Pages Could Allow Cross-Site Scripting Attack (816456)

    Originally posted: July 16, 2003

    Summary

    Who should read this bulletin: System administrators running Microsoft® Internet Security and Acceleration (ISA) Server 2000

    Impact of vulnerability: Allows an attacker to execute code of their choice

    Maximum Severity Rating: Important

    Recommendation: System administrators should install the patch at the earliest available opportunity.

    End User Bulletin: An end user version of this bulletin is available at:

    http://www.microsoft.com/security/security_bulletins/ms03-028.asp.

    Affected Software:
    - Microsoft Internet Security and Acceleration (ISA) Server 2000

    Technical description:

    ISA Server contains a number of HTML-based error pages that allow the server to respond to a client requesting a Web resource with a customized error. A cross-site scripting vulnerability exists in many of these error pages that are returned by ISA Server under specific error conditions.

    To exploit this flaw, an attacker would have to first be aware of a specific ISA server and its access policies or host an ISA server of their own and create specific access policies designed to exploit this vulnerability. The attacker could then craft a request to trigger a page refusal. Once the attack was crafted, the attacker would have to host a Web site containing the link, or send the link to the user in the form of an HTML e-mail. After the user previewed or opened the e-mail, the malicious site could be visited automatically without further user interaction. In the Web-based attack scenario, an attacker would have no way to force a user to visit the Web site.

    Mitigating factors:
    - The vulnerability could only be exploited if the attacker could entice another user into visiting a Web page and clicking a link on it, or opening an HTML-based e-mail.
    - The request must be one that would cause the ISA server to respond with one of several affected error pages.
    - The vulnerability would not normally enable an attacker to gain any privileges on an affected ISA Server computer, breach the firewall, or compromise any cached content, unless the user is operating on the ISA server itself and is using the Web Proxy service to access the Internet.

    Vulnerability identifier: CAN-2003-0526

    This email is sent to NTBugtraq automatically as a service to my subscribers. (v1.18)

    Cheers,
    Russ - Surgeon General of TruSecure Corporation/NTBugtraq Editor

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  • Next message: Russ: "Alert: Microsoft Security Bulletin - MS03-027"

    Relevant Pages

    • [NT] Cumulative Security Update for ISA Server 2000 (MS05-034)
      ... Get your security news from a reliable source. ... ISA Server 2000 provides "an enterprise firewall and a high-performance ... A vulnerability exists in ISA Server 2000 because of the way that it ... potentially allow an attacker to poison the cache of the affected ISA ...
      (Securiteam)
    • Re: Microsoft Security Bulletin MS03-028 - 816456
      ... Configuring ISA Server: http://tinyurl.com/1llp ... The Microsoft Security Response Center has released Microsoft Security ... : Bulletin MS03-028 ... Jerry Bryant - MCSE, ...
      (microsoft.public.security)
    • ISA Server - Error Page Cross Site Scripting
      ... A default error page can be used to conduct cross site scripting attacks ... ISA Server contains a number of HTML-based error pages that allow the ... Summer's Hottest Certification Just Got HOTTER! ...
      (NT-Bugtraq)