opera_browser

The SSL protocol, as used in certain configurations in Microsoft Windows and Microsoft Internet Explorer, Mozilla Firefox, Google Chrome, Opera, and other products, encrypts data by using CBC mode with chained initialization vectors, which allows man-in-the-middle attackers to obtain plaintext HTTP headers via a blockwise chosen-boundary attack (BCBA) on an HTTPS session, in conjunction with JavaScript code that uses (1) the HTML5 WebSocket API, (2) the Java URLConnection API, or (3) the Silverlight WebClient API, aka a "BEAST" attack.

Opera before 11.51 allows remote attackers to cause an insecure site to appear secure or trusted via unspecified actions related to Extended Validation and loading content from trusted sources in an unspecified sequence that causes the address field and page information dialog to contain security information based on the trusted site, instead of the insecure site.

Opera cannot properly restrict modifications to cookies established in HTTPS sessions, which allows man-in-the-middle attackers to overwrite or delete arbitrary cookies via a Set-Cookie header in an HTTP response, related to lack of the HTTP Strict Transport Security (HSTS) includeSubDomains feature, aka a "cookie forcing" issue.

Opera 11.11 allows remote attackers to cause a denial of service (application crash) by setting the FACE attribute of a FONT element within an IFRAME element after changing the SRC attribute of this IFRAME element to an about:blank value.

Opera before 11.10 allows remote attackers to cause a denial of service (application crash) via an HTML document that has an empty parameter value for an embedded Java applet.

Opera before 11.10 does not properly handle hidden animated GIF images, which allows remote attackers to cause a denial of service (CPU consumption) via an image file that triggers continual repaints.

Unspecified vulnerability in Opera before 11.10 allows remote attackers to cause a denial of service (application crash) via unknown content on a web page, as demonstrated by games on zylom.com.

Unspecified vulnerability in Opera before 11.10 allows remote attackers to cause a denial of service (application crash) via unknown content on a web page, as demonstrated by futura-sciences.com, seoptimise.com, and mitosyfraudes.org.

Unspecified vulnerability in Opera before 11.10 allows remote attackers to cause a denial of service (application crash) via unknown content on a web page, as demonstrated by a certain Tomato Firmware page.

The Cascading Style Sheets (CSS) implementation in Opera before 11.10 allows remote attackers to cause a denial of service (application crash) via vectors involving use of the :hover pseudo-class, in conjunction with transforms, for a floated element.