Microsoft Exchange Server Outlook Web Access HTML Injection Vulnerability



Date Discovered

June 14, 2005


Outlook Web Access is prone to an HTML injection vulnerability. This issue is due to a failure in the application to properly sanitize user-supplied input. An attacker may leverage this issue to have arbitrary script code executed in the affected application of an unsuspecting user in the context of the affected user. This issue is reported to affect Outlook Web Access for Exchange Server 5.5.

Technologies Affected

  • Microsoft Exchange Server 5.5 SP4
  • Microsoft Outlook Web Access for Exchange Server 5.5


Disable any services that are not needed.
Outlook Web Access should be disabled on each Exchange Server if it is not explicitly required.

Do not open email messages from unknown or untrusted individuals.
Users should avoid opening email messages that arrive unsolicited or originate from an unfamiliar or untrusted source. This may limit exposure to this vulnerability as exploitation may require the victim to open a malicious email message.

Microsoft has released fixes to address supported versions of the software.



Gael Delalleau is credited with discovery.

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