Researchers from Security Explorations, a Poland-based vulnerability research firm, claim to have found two new vulnerabilities in Java 7 Update 11 that can be exploited to bypass the software's security sandbox and execute arbitrary code on computers.
Oracle released Java 7 Update 11 on January 13 as an emergency security update in order to block a zero-day exploit used by cybercriminals to infect computers with malware.
Security Explorations successfully confirmed that a complete Java security sandbox bypass can be still be achieved under Java 7 Update 11 (JRE version 1.7.0_11-b21) by exploiting two new vulnerabilities discovered by the company's researchers, Adam Gowdiak, the company's founder, told the Full Disclosure mailing list last week. The vulnerabilities were reported to Oracle, together with working proof-of-concept exploit code, he said.
According to Security Explorations' disclosure policy, technical details about the vulnerabilities will not be publicly disclosed until the vendor issues a patch.
Researchers from security firm Immunity who analysed the exploit being used by cybercriminals since last week concluded that it also combined two vulnerabilities to achieve a Java sandbox escape. However, they later said that Java 7 Update 11 only addressed one of them and warned that if attackers find another vulnerability to replace the patched one, a new exploit can be created.
The vulnerabilities discovered by Security Explorations are separate from the one left unpatched by Oracle in Java 7 Update 11, Gowdiak said.
Some security researchers, including those from the US Computer Emergency Readiness Team (US-CERT), continued to advise users to disable the Java browser plug-in despite the release of Java 7 Update 11, citing concerns that similar attacks might occur in the future.
"There is definitely something worrying regarding the quality of Java SE 7 code," Gowdiak said. This could suggest the lack of a proper Secure Development Lifecycle program for Java or some other problems that are internal to Oracle, he said.
That said, the fact that Java 7 Update 11 asks for users confirmation before allowing Java applets to be executed inside browsers is definitely a step in the right direction and could block many attacks, Gowdiak said.