Sysadmins using the OpenSSL cryptographic library have an urgent job: patching a memory leak vulnerability that could reveal user IDs and passwords.
Dubbed “Heartbleed”, the vulnerability was discovered by Google Security's Neel Mehta and announced by CloudFlare.
As the terse OpenSSL advisory states: “A missing bounds check in the handling of the TLS heartbeat extension can be used to reveal up to 64k of memory to a connected client or server.”
A Q&A posted here by Codenomicon states that: “This compromises the secret keys used to identify the service providers and to encrypt the traffic, the names and passwords of the users and the actual content. This allows attackers to eavesdrop communications, steal data directly from the services and users and to impersonate services and users.”
Codenomicon notes that the bug has been “in the wild” since March 2012. More conservative sites, the Q&A notes, will be running older branches like 1.0.0 or 0.9.8 that aren't vulnerable.es the bug.
The fixed version is OpenSSL 1.0.1g. If you're stuck with a previous version of OpenSSL for some reason, you can block the vulnerability by re-compiling it using the OPENSSL_NO_HEARTBEATS flag. OpenSSL 1.0.2 will have the bug fixed in the upcoming 1.0.2-beta2 release. ®