Sun Microsystems has issued a critical update to the consumer version of its Java software, only days after its Java patching system was blasted by a security researcher.

The Java Platform Standard Edition (SE) Version 6, Update 2 release was made available on Sun's website on Friday, and is being pushed out to Java users who use the software's automatic update system, said Sun spokeswoman Jacki Decoster.

Sun supports four different versions of its Java SE software for desktop computers, and the company had already patched the other versions before releasing the Version 6, Update 2 release, which is the latest version of the product for consumer users.

That raised a red flag with security vendor eEye Digital Security, which said that the staggered release schedule gives criminals a chance to reverse-engineer the Java bug by looking at the patches that have been made public. Sun said it supports this schedule because it gives developers extra time to find bugs in the product before it lands on consumers' desktops.

eEye discovered the bug back in January. It is a critical flaw in the Java Network Launching Protocol, which is used to run Java programs over the web. Hackers could exploit this flaw by setting up a malicious website that could install unauthorised software on any Java-enabled PC that visited it, according to eEye.