The US Department of Homeland Security warned Thursday that a flaw in Java software could allow an attacker to execute commands on a PC system. System using Oracle Java 7 (1.7, 1.7.0) including Java Platform Standard Edition 7 (Java SE 7), Java SE Development Kit (JDK 7), Java SE Runtime Environment (JRE 7) as well as web browsers using the Java 7 plug-in are at high risk, the department said.

The vulnerability in the Java Security Manager allows a Java applet to grant itself permission to execute arbitrary code. 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 web site and upload a malicious Java applet (a "drive-by download" attack).

"This vulnerability is being attacked in the wild, and is reported to be incorporated into exploit kits," the department's Computer Emergency Readiness Team said in a notice on its website.

"We are currently unaware of a practical solution to this problem."

The recommended solution was to disable Java, which typically runs as a plug-in program in web browsers.

"A fix will be available shortly," Oracle said in a statement released late on Friday.

Oracle added that the recently discovered flaw only affects Java 7, the program's most-recent version, and Java software designed to run on browsers.