Revoke, reissue, invalidate: Stat! Security bods scramble to plug up Heartbleed
Paper is safe. Clay tablets too
All manner of attacks are possible as a result of the vulnerability.
"The 'Heartbleed' bug has epic repercussions since it affects one of the cryptographic suites that is used to run critical services on the Internet (OpenSSL 1.0.1)," explained Jaime Blasco, director at AlienVault Labs. "The bug permits an attacker to receive the contents of the server's memory, leading to compromise of critical information such as the digital keys that can be later used to decrypt communications or impersonate the real server."=
"By obtaining the memory of the server you can also access data such as username/passwords and even portions of the source code of the application running. The attack can be also combined with a Man-in-the-Middle attack to obtain credentials from the client before the server perform authentication," he added.
Vulnerable websites included Yahoo.com and OpenSSL.com among many others. Affected providers need to replace private keys and certificates after patching all OpenSSL services that rely on the vulnerable OpenSSL cryptographic library.
Mark Schloesser, security researcher at Rapid7, the developers of penetration-testing tool Metasploit, added: "The 'Heartbleed' SSL vulnerability affects widely deployed versions of the OpenSSL library which is used in the majority of software, including web-, email-, database- and chat-servers. It allows the attacker to read a portion of memory from the remote system without the need for any known credentials or other authentication forms.
"The leaked memory areas might contain a lot of different content, ranging from leftover data from previous communication over log messages, up to private key material employed by the service / daemon. For this reason, there are lots of possible attack scenarios that can result from the vulnerability.
"An attacker who gains access to the private key of the server certificate can subsequently mount man-in-the-middle attacks against clients and impersonate the server/service. Log messages might also contain credentials or affect the privacy of communications by other clients," he added.
OpenSSL 0.9.8 and 1.0.0 are still the most popular versions of the software on web servers, and these are not affected. "However we count at least a few hundred thousand servers using affected library versions so that it poses a significant threat," Schloesser warns.
"As the same problem affects other protocols / services such as mail servers and databases, we assume that overall we're looking at millions of vulnerable systems connected to the public internet.
"Affected systems get updated but that's just the start of security remediation. To mitigate against attacks resulting from leaked material, any SSL keys from affected systems should be replaced and revoked," he added.
A short video by Zulfikar Ramzan, CTO at cloud security services firm Elastica, explaining how the Heartbleed vulnerability works can be found here.
The newly established CERT UK security clearing house put out its first major advisory on Heartbleed.
A statement by developers of OpenSSL can be found here.
The whole security emergency has already spawned a xkcd funny featuring the tongue-in-cheek observation that at least pen and paper are not affected by the megavuln. ®