Oracle rushes out emergency patch to fix Java security flaw

Java has a security flaw requiring an emergency patch. That's unusual, isn't it?

Oracle has rushed out an out-of-band patch to fix serious security flaws in its Java client running on Windows devices.

The patch was released late on Friday, with the issue explained in its Security Alert CVE-2016-0603. The patch is intended to fix vulnerabilities in Java 6, 7 and 8 running on Windows.

"To be successfully exploited, this vulnerability requires that an unsuspecting user be tricked into visiting a malicious website and download files into the user's system before installing Java SE 6, 7 or 8," explained Oracle.

It continued: "Though relatively complex to exploit, this vulnerability may result, if successfully exploited, in a complete compromise of the unsuspecting user's system."

The flaw has received a CVSS Base Score of 7.6, which translates as "High".

Oracle explained that customers with Java already installed are not at risk but that anyone installing the software should use the official website to avoid the risk of infection.

"As a reminder, Oracle recommends that Java home users visit Java.com to ensure that they are running the most recent version of Java SE and that all older versions have been completely removed," the firm said.

Qualys chief technology officer Wolfgang Kandek urged anyone installing Java in the coming days to be aware of the Oracle fix.

"As Oracle points out, existing installations are not at risk. New installations should use the latest fixed packages published by Oracle," he said.

"This would address the situation where an end-user might have visited a malicious site which could have prepared the machine for an attack by downloading altered versions of one of the DLLs [dynamic link libraries] involved."

The fix comes around two weeks after Oracle issued its standard quarterly security update that contained 248 fixes. Oracle recently pledged to kill off Java plug-ins in a move that mirrors a pledge made by Adobe in December to phase out its much-maligned Flash browser plug-in.