Proface

Vulnerability in the Java Security Manager allows a Java applet to grant itself permission to execute arbitrary code. An attacker could use social engineering techniques to entice a user to visit a link to a website hosting a malicious Java applet. An attacker could also compromise a legitimate web site and upload a malicious Java applet (a "drive-by download" attack).

Any web browser using the Java 7 plug-in is affected. The Java Deployment Toolkit plug-in and Java Web Start can also be used as attack vectors.

Reports indicate this vulnerability is being actively exploited, and exploit code is publicly available.

 For more details and recommended actions, please read http://www.us-cert.gov/cas/techalerts/TA13-010A.html

 More safty tips from the author: http://econtents.net/article.php?id=216