Sun Microsystems issued a patch Tuesday to address <A HREF="http://news.zdnet.com/2100-1009_22-6036730.html?tag=nl.e589">seven "highly critical" flaws</A> in its Java Runtime Environment that could allow a malicious attacker to gain remote control over a user's system. The flaws affect systems running on Windows, Solaris and Linux that are using certain versions of Sun's Java Development Kit 1.5, Software Development Kit 1.3 and 1.4, and JRE 1.3, 1.4, 1.5 and 5.0, or earlier, according to an advisory issued by Secunia, which rated the flaws as "highly critical." Sun's JRE software, especially version 1.4, is found on a number of computers and allows users to run Java applications, which operate in a "sandbox"--a separate area cordoned off from the rest of the user's system.