The Worst Unpatched Flaws of Recent Times: A Closer Look


With new vulnerabilities being discovered all the time, staying ahead of patching is paramount. Yet, despite ongoing efforts, some vulnerabilities slip through the cracks, leading to potentially catastrophic consequences. From high-profile incidents to widespread threats, the past few years have seen their fair share of unpatched flaws making headlines worldwide. Let’s delve into some of the most notable cases, examining who was affected and the severity of the fallout.

1. The Log4j Debacle:

In December 2021, the cyber security community was rocked by the discovery of a critical vulnerability in Log4j, a widely used Java-based logging framework. Dubbed Log4Shell, this flaw allowed attackers to execute arbitrary code on affected servers, earning it a CVSS severity rating of 10 – the highest possible score. The repercussions were staggering, with estimates suggesting hundreds of millions of assets could be compromised, including systems operated by trusted cloud service providers.

Among the victims was ONUS, one of Vietnam’s largest cryptocurrency trading platforms. Exploiting the Log4j vulnerability, attackers infiltrated ONUS’s payment system, compromising sensitive data belonging to millions of customers. Despite efforts to patch the flaw after receiving advisories, ONUS fell victim to the attackers, who demanded a hefty ransom to withhold the stolen data. The incident underscored the critical importance of prompt patching and robust cyber security measures in the face of evolving threats.

2. The UK Electoral Commission Breach:

In a case closer to home, the UK Electoral Commission found itself embroiled in a complex cyber attack discovered in October 2022, nearly ten months after the initial breach. Evidence suggested that threat actors gained access to the Commission’s systems as far back as August 2021, exploiting unpatched vulnerabilities in Microsoft Exchange servers. This prolonged exposure allowed attackers to exfiltrate personal information belonging to approximately 40 million voters, raising significant concerns about data privacy and electoral integrity.

The Patching Dilemma:

While patches exist to mitigate vulnerabilities, the timely deployment of these updates remains a persistent challenge for organisations. The time taken to patch software can vary considerably, influenced by factors such as the severity of the vulnerability, internal processes, and resource constraints. From urgent fixes completed within days to prolonged delays stretching over months, the patching landscape is rife with complexities and nuances.

Strategies for Effective Patch Management:

To navigate the patching maze effectively, organisations can adopt a proactive approach supported by robust strategies and resources:

  • Inventory and Asset Management: Maintain up-to-date inventories of hardware and software assets to facilitate targeted patching efforts.
  • Vulnerability Assessment: Conduct regular vulnerability assessments to identify and prioritise security weaknesses.
  • Risk Prioritisation: Prioritise vulnerabilities based on severity and potential impact to focus resources effectively.
  • Patch Management Policy: Establish comprehensive policies outlining patching procedures, responsibilities, and timelines.
  • Automated Patch Deployment: Utilise patch management tools to automate the deployment of updates and streamline the patching process.
  • Testing Procedures: Implement testing environments to evaluate patches for compatibility and mitigate risks of unintended consequences.
  • Regular Backups: Implement regular data backups to safeguard critical information and facilitate recovery in the event of patching-related issues.
  • Vendor Relationships: Foster effective communication channels with software vendors to stay informed about security advisories and patches.


In a world where new vulnerabilities are discovered almost constantly, the threat posed by unpatched vulnerabilities looms large. By understanding the challenges, prioritising patch management, and adopting proactive strategies, organisations can mitigate risks and safeguard against potential breaches. In an era defined by relentless cyber threats, vigilance and preparedness are paramount to ensuring a secure digital future.

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Written by Daniel Komenda

Daniel Komenda is the Focal Analyst Lead at norm. His team of dedicated, trusted security advisors for smartbloc.LIVE clients specialises in comprehensive analysis of IT environments and effectively increasing their cyber resilience. One of the main areas they cover on a daily basis is Vulnerability and Patch Management.