Ubuntu Security Notice USN-725-1 - It was discovered that Kmail did not adequately prevent execution of arbitrary code when a user clicked on a URL to an executable within an HTML mail. If a user clicked on a malicious URL and chose to execute the file, a remote attacker could execute arbitrary code with user privileges. This update changes KMail's behavior to instead launch a helper program to view the file if the user chooses to execute such a link.
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