From Technology Review…

In technical terms, a programming error reduced the amount of entropy used to create the cryptographic keys in a piece of code called the OpenSSL library, which is used by programs like the Apache Web server, the SSH remote access program, the IPsec Virtual Private Network (VPN), secure e-mail programs, some software used for anonymously accessing the Internet, and so on.

In plainer language: after a week of analysis, we now know that two changed lines of code have created profound security vulnerabilities in at least four different open-source operating systems, 25 different application programs, and millions of individual computer systems on the Internet. And even though the vulnerability was discovered on May 13 and a patch has been distributed, installing the patch doesn’t repair the damage to the compromised systems. What’s even more alarming is that some computers may be compromised even though they aren’t running the suspect code….