Ubuntu Security Notice 493-1 - A flaw was discovered in handling of "about:blank" windows used by addons. A malicious web site could exploit this to modify the contents, or steal confidential data (such as passwords), of other web pages. Jesper Johansson discovered that spaces and double-quotes were not correctly handled when launching external programs. In rare configurations, after tricking a user into opening a malicious web page, an attacker could execute helpers with arbitrary arguments with the user's privileges.
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