Heartbleed is the nickname for a vulnerability in OpenSSL, an open-source implementation of the SSL and TLS protocols that’s used to secure data sent between clients and servers. The bug was jointly discovered by security firm Codenomicon and Google and publicly detailed in 2014, when related patches and fixes were released. Shodan, a search engine for internet-connected devices, says that a Jan. 22 search identified 199,594 devices that still remain vulnerable to the bug. The most recent Shodan search reported that the number of vulnerable devices had dropped to about 180,000, meaning that about 20,000 were apparently remediated.”]