Any system using Oracle Java including
- JDK and JRE 7 Update 13 and earlier
- JDK and JRE 6 Update 39 and earlier
- JDK and JRE 5.0 Update 39 and earlier
- SDK and JRE 1.4.2_41 and earlier
Web browsers using the Java plug-in are at high risk.
Multiple vulnerabilities in Java could allow an attacker to execute arbitrary code on a vulnerable system.
The Oracle Java SE Critical Patch Update Advisory Update for February 2013 addresses multiple vulnerabilities in the Java Runtime Environment (JRE). An additional five fixes that had been previously planned for delivery are in this update. This distribution therefore completes the content for all originally planned fixes to be included in the Java SE Critical Patch Update for February 2013.
Both Java applets delivered via web browsers and stand-alone Java applications are affected, however web browsers using the Java plug-in are at particularly high risk.
The Java plug-in, the Java Deployment Toolkit plug-in, and Java Web Start can be used as attack vectors. 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 website and upload a malicious Java applet (a "drive-by download" attack).
Some vulnerabilities affect stand-alone Java applications, depending on how the Java application functions and how it processes untrusted data.
Reports indicate that at least one of these vulnerabilities is being actively exploited.
By convincing a user to load a malicious Java applet or Java Network Launching Protocol (JNLP) file, an attacker could execute arbitrary code on a vulnerable system with the privileges of the Java plug-in process.
Stand-alone java applications may also be affected.
The Oracle Java SE Critical Patch Update Advisory Update for February 2013 states that Java 7 Update 15 and Java 6 Update 41 address these vulnerabilities.
Disable Java in web browsers
These and previous Java vulnerabilities have been widely targeted by attackers, and new Java vulnerabilities are likely to be discovered. To defend against this and future Java vulnerabilities, consider disabling Java in web browsers until adequate updates have been installed. As with any software, unnecessary features should be disabled or removed as appropriate for your environment.
Starting with Java 7 Update 10, it is possible to disable Java content in web browsers through the Java control panel applet. From Setting the Security Level of the Java Client:
For installations where the highest level of security is required, it is possible to entirely prevent any Java apps (signed or unsigned) from running in a browser by de-selecting Enable Java content in the browser in the Java Control Panel under the Security tab.
If you are unable to update to at least Java 7 Update 10, please see the solution section of Vulnerability Note VU#636312 for instructions on how to disable Java on a per-browser basis.
Restrict access to Java applets
Network administrators unable to disable Java in web browsers may be able to help mitigate these and other Java vulnerabilities by restricting access to Java applets using a web proxy. Most web proxies have features that can be used to block or whitelist requests for
.class files based on network location. Filtering requests that contain a Java User-Agent header may also be effective. For environments where Java is required on the local intranet, the proxy can be configured to allow access to Java applets hosted locally, but block access to Java applets on the internet.
February 20, 2013: Initial release
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