Published:2008/10/20  Last Updated:2008/10/23

Internet Explorer vulnerable in handling CDO protocol


Internet Explorer is vulnerable in handling CDO (Collaboration Data Objects) protocol, which allows the download dialog box to be bypassed.

Products Affected

  • Microsoft Office XP SP3


When Internet Explorer (IE) accesses a website using CDO (Collaboration Data Objects), IE processes the contents as CDO data, ignoring their actual content types, and IE does not properly handle the Content-Disposition header field.
This could cause a download dialog box not to be displayed prior to downloading. The CDO protocol handler is included in an Office component, and Microsoft provides the fix for this component.


An arbitrary script could be executed without explicit user consent, as the download dialog box is not displayed on the user's IE.


Update the Software
Update to the latest version according to the information provided by the vendor.


JPCERT/CC Addendum

Vulnerability Analysis by JPCERT/CC

Analyzed on 2008.10.20

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-Medium - some expertise and/or luck required (most buffer overflows, guessing correctly in small space, expertise in Windows function calls)
  • Medium-High

Description of each analysis measures


NetAgent Co., Ltd. reported this vulnerability to IPA.
JPCERT/CC coordinated with the Microsoft Corporation under Information Security Early Warning Partnership.

Other Information

JPCERT Reports
CERT Advisory
CPNI Advisory
CVE CVE-2008-4020
JVN iPedia JVNDB-2008-000070

Update History