Opera is a multi-platform web browser.
Multiple vulnerabilities have been found in the Opera web browser. Opera fails to deny write access to the "location" browser object. An attacker can overwrite methods in this object and gain script access to any page that uses one of these methods. Furthermore, access to file:// URLs is possible even from pages loaded using other protocols. Finally, spoofing a legitimate web page is still possible, despite the fixes announced in GLSA 200407-15.
By enticing an user to visit specially crafted web pages, an attacker can read files located on the victim's file system, read emails written or received by M2, Opera's mail program, steal cookies, spoof URLs, track user browsing history, etc.
There is no known workaround at this time. All users are encouraged to upgrade to the latest available version.
All Opera users should upgrade to the latest stable version:
# emerge sync
# emerge -pv ">=www-client/opera-7.54"
# emerge ">=www-client/opera-7.54"