Computer security experts are advising administrators to patch a severe flaw in a software library used by millions of websites to encrypt sensitive communications.
The flaw, nicknamed “Heartbleed,” is contained in several versions of OpenSSL, a cryptographic library that enables SSL (Secure Sockets Layer) or TLS (Transport Security Layer) encryption. Most websites use either SSL or TLS, which is indicated in browsers with a padlock symbol.
The flaw, which was introduced in December 2011, has been fixed in OpenSSL 1.0.1g, which was released on Monday. The vulnerable versions of OpenSSL are 1.0.1 through 1.0.1f with two exceptions: OpenSSL 1.0.0 branch and 0.9.8, according to a special website set up by researchers who found the problem.