Microsoft Internet Explorer Source Element Cross-Domain Information Disclosure Vulnerability



Date Discovered

August 8, 2006


Microsoft Internet Explorer is prone to an information-disclosure vulnerability because it fails to properly enforce cross-domain policies. This issue may allow attackers to access arbitrary websites in the context of a targeted user's browser session. This may allow attackers to perform actions in web applications with the privileges of exploited users or to gain access to potentially sensitive information. This may aid attackers in further attacks.

Technologies Affected

  • Microsoft Internet Explorer 5.0
  • Microsoft Internet Explorer 5.0.1
  • Microsoft Internet Explorer 5.0.1 SP1
  • Microsoft Internet Explorer 5.0.1 SP2
  • Microsoft Internet Explorer 5.0.1 SP3
  • Microsoft Internet Explorer 5.0.1 SP4
  • Microsoft Internet Explorer 5.0.1 SP4
  • Microsoft Internet Explorer 6.0
  • Microsoft Internet Explorer 6.0 SP1
  • Nortel Networks CallPilot 1002rp
  • Nortel Networks CallPilot 200i
  • Nortel Networks CallPilot 201i
  • Nortel Networks CallPilot 702t
  • Nortel Networks CallPilot 703t
  • Nortel Networks Centrex IP Client Manager
  • Nortel Networks Centrex IP Element Manager
  • Nortel Networks Contact Center - Agent Desktop Display
  • Nortel Networks Contact Center - Symposium Agent


Run all software as a nonprivileged user with minimal access rights.
Ensure that all non-administrative tasks, such as browsing the web and reading email, are performed as an unprivileged user with minimal access rights.

Do not follow links provided by unknown or untrusted sources.
Users should never visit sites of questionable integrity or follow links provided by unfamiliar or untrusted sources.

Set web browser security to disable the execution of script code or active content.
Disabling scripting and active content in the Internet Zone may limit exposure to this and other vulnerabilities.

Disable any services that are not needed.
Disable support for HTML email in the email client. This may limit email-based attack vectors for this and other vulnerabilities.

The vendor has released an advisory addressing this issue in supported versions of the affected application. Please see the referenced advisory for more information. MS06-042 has been reissued to address a vulnerability introduced with the previous fixes. Please see BID 19667 (Microsoft Internet Explorer HTTP 1.1 and Compression Long URI Buffer Overflow Vulnerability) for further information on this issue. Microsoft Security Bulletin MS06-042 has been updated to address a flaw in Mshtml.dll that was introduced in the previous fixes. Please see the referenced advisory for more information.



This issue was disclosed by the vendor.

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