Hello All, Today, a vulnerability report with an accompanying Proof of Concept code was sent to Oracle notifying the company of a new security weakness affecting Java SE 7 software. The new flaw was verified to affect all versions of Java SE 7 (including the recently released 1.7.0_21-b11). It can be used to achieve a complete Java security sandbox bypass on a target system. Successful exploitation in a web browser scenario requires proper user interaction (a user needs to accept the risk of executing a potentially malicious Java application when a security warning window is displayed). What's interesting is that the new issue is present not only in JRE Plugin / JDK software, but also the recently announced Server JRE as well [1]. Those concerned about a feasibility of exploitation of Java flaws in a server environment should consult Guideline 3-8 of "Secure Coding Guidelines for a Java Programming Language" [2]. It lists the following software components and APIs as potentially prone to the execution of untrusted Java code: - Sun implementation of the XSLT interpreter, - Long Term Persistence of JavaBeans Components, - RMI and LDAP (RFC 2713), - Many SQL implementations. In Apr 2012 [3], we reported our first vulnerability report to Oracle corporation signaling multiple security problems in Java SE 7 and the Reflection API in particular. It's been a year since then and to our true surprise, we were still able to discover one of the simplest and most powerful instances of Java Reflection API based vulnerabilities. It looks Oracle was primarily focused on hunting down potentially dangerous Reflection API calls in the "allowed" classes space. If so, no surprise that Issue 61 was overlooked. Thank you. Best Regards Adam Gowdiak --------------------------------------------- Security Explorations http://www.security-explorations.com "We bring security research to the new level" --------------------------------------------- References: [1] Server JRE (Java SE Runtime Environment) 7 Downloads http://www.oracle.com/technetwork/java/javase/downloads/server-jre7-downloads-1931105.html [2] Secure Coding Guidelines for the Java Programming Language, Version 4.0 http://www.oracle.com/technetwork/java/seccodeguide-139067.html [3] SE-2012-01 Vendors status http://www.security-explorations.com/en/SE-2012-01-status.html