OpenSSL vulnerability lets attackers quietly steal servers' private keys

Posted by   Virus Bulletin on   Apr 7, 2014

Security firm advises regenerating keys and replacing certificates on vulnerable servers.

A very serious vulnerability in OpenSSL has caused panic among network administrators: CVE-2014-0160 allows an attacker to read the memory of a vulnerable server and thus obtain private encryption keys, passwords and other kinds of sensitive information.

OpenSSL is a widely used open-source implementation of the SSL and TLS cryptography protocols. It is used by many web servers and other online services to prevent adversaries from eavesdropping on sensitive information. The vulnerability was introduced in OpenSSL 1.0.1, which was released in March 2012. It was fixed in OpenSSL 1.0.1g, released yesterday.

The vulnerability has been named 'Heartbleed', after the heartbeat extension that adds session management to TLS connections, in the implementation of which the vulnerability resides.

An attacker can connect to a vulnerable server and use the vulnerability to read up to 64 kilobytes of the server's memory. While the attacker has no control of which memory segment it obtains, there is no limit to the number of times the attack can be performed; hence it can effectively be used to perform a remote memory dump. To make matters worse, the way the heartbeat protocol is implemented means that attack activity is not logged.

Luckily, the attack can be detected on the network, albeit not retroactively. Security firm Fox-IT has released a number of Snort signatures that detect successful exploitation of the vulnerability.

The vulnerability was discovered independently by researchers from Google and Finnish security firm Codenomicon. The latter set up a useful website with a number of frequently asked questions about the vulnerability. There is no reason to assume that the vulnerability hasn't also been discovered by an entity that doesn't have the best interests of the Internet at heart.

Unlike the recent 'goto fail' vulnerability in OS X (and a similar one in GnuTLS), the vulnerability doesn't require a man-in-the-middle attack to be performed. Once an attacker has used the vulnerability to obtain the server's private signing keys, these can of course be used to perform man-in-the-middle attacks.

Fixing the vulnerability is easy - simply upgrade to OpenSSL 1.0.1g. But that doesn't stop attackers who have previously obtained the private keys. Hence it is important to follow the advice given by Fox-IT - to regenerate the private keys and replace the SSL certificates - even if it is a rather painful and possibly expensive procedure.

A website has been set up to check if your server is vulnerable, though that reportedly can give false positives. In the meantime, given the huge impact of this vulnerability, one is right to wonder if OpenSSL shouldn't be considered critical infrastructure.

Posted on 08 April 2014 by Martijn Grooten

twitter.png
fb.png
linkedin.png
googleplus.png
reddit.png

 

Latest posts:

Subtle change could see a reduction in installation of malicious Chrome extensions

Google has made a subtle change to its Chrome browser, banning the inline installation of new extensions, thus making it harder for malware authors to trick users into unwittingly installing malicious extensions.

Paper: EternalBlue: a prominent threat actor of 2017–2018

We publish a paper by researchers from Quick Heal Security Labs in India, who study the EternalBlue and DoublePulsar exploits in full detail.

'North Korea' a hot subject among VB2018 talks

Several VB2018 papers deal explicitly or implicitly with threats that have been attributed to North Korean actors.

Expired domain led to SpamCannibal's blacklist eating the whole world

The domain of the little-used SpamCannibal DNS blacklist had expired, resulting in it effectively listing every single IP address.

MnuBot banking trojan communicates via SQL server

Researchers at IBM X-Force have discovered MnuBot, a banking trojan targeting users in Brazil, which is noteworthy for using SQL Server for command and control communication.

We have placed cookies on your device in order to improve the functionality of this site, as outlined in our cookies policy. However, you may delete and block all cookies from this site and your use of the site will be unaffected. By continuing to browse this site, you are agreeing to Virus Bulletin's use of data as outlined in our privacy policy.