Published:2007/06/18  Last Updated:2008/05/21

Internet Explorer vulnerable in MHTML handling


Internet Explorer is vulnerable in handling MHTML (MIME Encapsulation of Aggregate HTML) protocol, which may allow an arbitrary script execution.

Products Affected

Some versions of Outlook Express are affected because the vulnerability is contained in the Outlook Express component used by Internet Explorer.

  • Outlook Express 6, Windows XP / Windows Server 2003
  • Windows Mail, Windows Vista


When Internet Explorer accesses a website with the MHTML protocol, Internet Explorer processes the contents as MHTML data, ignoring their actual content types. This behavior may result in executing the scripts embedded in the contents.
The MHTML protocol handler is included in the Outlook Express component, and Microsoft provides the fix of the vulnerability for this component.


An arbitrary script may be executed on the user's web browser.


Update the Software
Apply the latest updates provided by the vendor.


JPCERT/CC Addendum

Vulnerability Analysis by JPCERT/CC

Analyzed on 2007.06.18

Measures Conditions Severity
Access Required Routed - can be attacked over the Internet using packets
  • High
Authentication None - anonymous or no authentication (IP addresses do not count)
  • High
User Interaction Required Simple - the user must be convinced to take a standard action that does not feel harmful to most users, such as click on a link or view a file
  • Medium
Exploit Complexity Low - little to no expertise and/or luck required to exploit (cross-site scripting)
  • High

Description of each analysis measures


stardust hoshikuzu and Yosuke Hasegawa reported this vulnerability to IPA.
JPCERT/CC coordinated with the vendors under Information Security Early Warning Partnership.

Other Information

JPCERT Alert JPCERT-AT-2007-0014
JPCERT Reports
CERT Advisory Technical Cyber Security Alert TA07-163A
CPNI Advisory
CVE CVE-2007-2225
JVN iPedia JVNDB-2007-000446

Update History