A year ago we marked ten years since the Heartbleed bug, and marking another year on from that, we look at the 11 ways that Heartbleed changed cybersecurity.

The 2014 OpenSSL bug, which was introduced into the software in 2012, before the public disclosure in April 2014, and raised questions and conversations on open source software security. It also increased awareness of the Linux Foundation and open source code and tools overall.

These are my takeaways of how one vulnerability in TLS, also known as CVE-2014-0160, went on to be one of the most notorious security vulnerabilities of the 2010s.

1. It helped us understand the concept of DevOps, how code is developed. Since 2014 the concept of “shift left” has become part of the security development lifecycle, and the call for secure software has been constant, from conversations in 2014 to an open letter last week.

2. Made us understand how unknown deployments worked, and how a lack of visibility was a problem. Asset management became a key part of cybersecurity vendor offerings towards the end of the last decade, with Axonius winning the 2019 Innovation Sandbox at RSA Conference, and Tenable spent around $450 million on BitDiscovery.

3. Made us understand the vulnerabilities, weaknesses and problems of managing third party open source code. From Heartbleed, we got a much clearer understanding of code repositories and libraries, and how code was often re-used in new applications.

4. Made us understand how there was a challenge about patching immediately. The announcement of Heartbleed likely caused more conversations at board level to understand how vulnerable a company was to this vulnerability, and caused better understanding between CISO and CEO. Also this may have put more emphasis on rapid patching: research shared with SC UK from Tenable stated that the average remediation rate is now 157 days for CVEs (disclosed between November 1st 2023, and October 31st 2024).

5. It led to some bad reporting. At the time we saw a lot of use of the term ‘Heartbleed virus” and there was a general misunderstanding of what was happening. It demonstrated the determination to get a story live first, and without technical knowledge, a writer could get this very wrong.

6. It saw a company create a PR message, organise an event and get acquired. Now all love to Codenomicon (now part of Black Duck) for their discovery and publicity of Heartbleed, but the discovery gave time for a PR message to be created, whilst this writer attended an event at Black Hat 2014 organised by Codenomicon, and the company would be snapped up just over 12 months later. 

7. Made us learn about data exfiltration. According to GeeksforGeeks blog, ‘Heartbleed allows attackers to extract sensitive information directly from the memory of affected servers or clients without notice, including private keys, passwords, consultation tokens, and other personal records.’ At this time, that was the duty of the cyber-criminal, but apparently exploitation could be pretty severe/

8. Reality of SSL and Open Source security was exposed. As asked here, were there ‘actually any other exploitable SSL or TLS vulnerabilities’ other than Heartbleed, and even if not, did the discovery of Heartbleed cause more research to be done? Also how come we’ve not heard anything about OpenSSL since?

9. Had a cool logo and a cool name. Those with longer memories will recall 2016’s Badlock, which could allow elevation of privilege if an attacker launched a man-in-the-middle attack and force a downgrade of the authentication level of the SAM and LSAD channels. This was only given a severity rating of 7.5 and some premature hype didn’t live up to the billing. Also as Patrick McKenzie said, the Heartbleed logo was simple and memorable

10. Software Bill of Material developments. As a 2023 blog by the Open Source Security Foundation stated ‘Heartbleed sparked more conversations about SBOMs’ as if an SBOM can provide a list of the underlying software components a given application is dependent on, is packaged with or requires. Could one of these for OpenSSL have resolved the issues without the caused panic to fix?

11. Made us understand why we need threat intelligence about what our adversaries know about us. Most of the threat intelligence providers were acquired around 2015-2016, with iSight Partners’ acquisition by FireEye one of the most notable. However there is only so much knowledge a company can have of its security stance, and threat intelligence remains a key tool in security defence.

Dan Raywood

Dan Raywood is a B2B journalist with 25 years of experience, including covering cybersecurity for the past 17 years. He has extensively covered topics from Advanced Persistent Threats and nation-state hackers to major data breaches and regulatory changes.

He has spoken at events including 44CON, Infosecurity Europe, RANT Forum, BSides Scotland, Steelcon and the National Cyber Security Show, and served as editor of SC Media UK, Infosecurity Magazine and IT Security Guru. He was also an analyst with 451 Research and a product marketing lead at Tenable.