Software Engineering Institute

The Sun Java Reflection API allows Java classes to determine information about other Java classes, such as public methods. There are three, unspecified vulnerabilities in the Reflection API that may allow a Java applet to bypass Java applet security restrictions. Once the security restrictions are bypassed, the malicious applet may be able to access and manipulate system resources.

For more information on the Java security model see Sun's Java documentation, particularly the Applet Security FAQ. For more information regarding these vulnerabilities and how to correct them, please refer to Sun Alert 102003.

By convincing a user to run a Java applet, a remote, unauthenticated attacker may be able to execute arbitrary code with the privileges of the user running the applet. Web browsers with Java support may run applets from untrusted web sites.

Upgrade Java
Sun has released two separate updates to correct these issues. Sun Alert 102003 describes the following patches:

The first issue is addressed in the following releases:

• SDK and JRE 1.3.1_16 and later
• SDK and JRE 1.4.2_09 and later
• JDK and JRE 5.0 Update 4 and later

• SDK and JRE 1.4.2_09 and later
• JDK and JRE 5.0 Update 4 and later

Do not access Java Applets from untrusted sources

Attackers must deliver a malicious Java applet to a vulnerable system in order to take advantage of this vulnerability. By only accessing Java applets from known and trusted sources the chances of exploitation are reduced.

Disable Java in web browser

Java applets are commonly executed within a web browser. Disabling Java within the web browser may prevent an attacker from delivering a malicious applet to a vulnerable system.