Running OpenSSL? Patch now to fix CRITICAL bug
All over the world, systems administrators are scrambling to fix the OpenSSL “Heartbleed” bug.
Sysadmins using the OpenSSL cryptographic library have an urgent job: patching a memory leak vulnerability that could reveal user IDs and passwords
Not just websites hit by OpenSSL's Heartbleed – your PC, phone and more may be in peril
Also: Google announces services' Heartbleed status
By Richard Chirgwin, 10 Apr 2014
While most attention surrounding OpenSSL's Heartbleed vulnerability has focussed on the server side, the SANS Institute has reminded the world that the client side is also vulnerable.
Williams said the data-leaking bug “is much scarier” than the gotofail in Apple's crypto software, and his opinion is that it will have been known to black hats before its public discovery and disclosure.
In a presentation given yesterday, Jake Williams – aka MalwareJake – noted that vulnerable OpenSSL implementations on the client side can be attacked using malicious servers to extract passwords and cryptographic keys.
Williams said a malicious server could easily send a message to vulnerable software on phones, laptops, PCs, home routers and other devices, and retrieve a 64KB block of sensitive data from the targeted system. It's an attack that would probably yield handy amounts of data if deployed against users of public Wi-Fi hotspots, for example.
Writing code to exploit vulnerabilities in clients is “not going to be that difficult to do,” he said.
Security penetration testers are going to find themselves in work “through 2020” with this bug, Williams said, and noted that it's going to be hard to identify vulnerabilities in some environments. For example, he said, it's going to be hard to tell if Windows client programs were compiled against vulnerable OpenSSL versions.
And that's not to mention all the "non-port-443" software that might be compiled to vulnerable versions of OpenSSL - e-mail servers, databases, LDAP services, and so on.
While The Register has a code-level description of Heartbleed here, it's also handy to have an easy pictorial, which Williams provided. In the OpenSSL RFC, there are two user-supplied inputs that create the problem as shown in the image below: