Zero-Day Vulnerability

Cyberattacks frequently make headlines, but one threat increasingly challenging security leaders — especially following the Log4j and SolarWinds incidents — is zero-day vulnerabilities. What is a zero day vulnerability and why is it relevant for third-party risk management?

What is a zero-day vulnerability?

A zero day (also referred to as 0-day) is a software vulnerability either unknown to its developer, or known and without a patch to fix it. The name derives from the fact that developers or vendors have "zero days" to fix the flaw before it is actively exploited.

Until the vulnerability is mitigated, attackers can use it to compromise data or additional systems, including operating systems, web browsers, office applications, open-source components, hardware, firmware, or Internet of Things (IoT) devices.

Zero day: vulnerability vs. exploit vs. attack

The term is often used along with words like vulnerability, exploit, and attack, so it’s helpful to understand the difference:

• Zero-day vulnerability: a software flaw that attackers discover before the vendor does. Because no patch exists yet, attacks exploiting it are likely to succeed.
• Zero-day exploit: the code that allows attackers to leverage the vulnerable piece of software to compromise systems; exploits are usually sold on the dark web.
• Zero-day attack: the use of a zero day exploit to disrupt, cause damage to, or steal data from a vulnerable system.

How to protect against zero-day attacks

Software is written by humans, and humans are fallible. Developers create software every day, but unbeknownst to them, it may contain vulnerabilities. This makes zero-day attacks inevitable, as attackers often spot those vulnerabilities before the developers detect and act on them.

So how can you minimize risk in your organization and across your digital supply chain?

Basic zero day protection measures include:

• Keeping all software and operating systems up to date, installing patches as soon as they become available. Security patches often cover newly identified vulnerabilities, and poor patching cadence has been proven to correlate with risk.
• Enforcing security standards as part of your vendor risk assessments and due diligence process, and updating your requirements as needed after a zero day is discovered.
• Performing continuous monitoring and reassessment of your vendors as opposed to point-in-time calendar evaluations.
• Using a layered defense strategy, combining antivirus, firewall, and other security solutions, with security mechanisms like zero trust or MFA.
• Educating users on cybersecurity best practices, especially amid flexible work arrangements, as many zero-day attacks capitalize on human error.

Organizations must establish a comprehensive and agile TPRM strategy that incorporates continuous monitoring, timely vendor risk assessments, and rapid response mechanisms. Effective integration of threat intelligence within TPRM frameworks allows organizations to swiftly identify potential third-party exposures and initiate immediate mitigation actions, thus significantly reducing the window of risk associated with zero-day vulnerabilities.

Collaboration and transparent communication with third-party vendors are essential. Establishing clear expectations for vendors to promptly report their vulnerability status and remediation plans helps organizations better manage exposure. Moreover, conducting regular scenario-based exercises with critical third-party vendors enhances preparedness and ensures that all stakeholders clearly understand their roles and responsibilities during a zero-day incident.

Steps to take if you are affected by a zero day

The first thing you need to do when a new zero day is reported is to assess the prevalence of the vulnerability in your organization and within your third-party digital supply chain. In other words, determine if your organization or your vendors are utilizing vulnerable versions of the software in question.

As part of your due diligence and ongoing reassessment processes, you need to make sure that your vendors are enforcing standards that keep your business safe. Should a zero-day vulnerability appear, you need to be able to promptly:

•  Identify vulnerable third-party vendors in your supply chain
•  Ask them how they are planning to react and mitigate the vulnerability
•  Update your requirements and request additional assurances

To effectively manage these events, implement a centralized, streamlined third-party risk management (TPRM) process. This allows for efficient, scalable responses, avoiding cumbersome manual follow-ups with vendors via emails and spreadsheets.

5 Tips for remediating zero-day vulnerabilities

Follow these zero day remediation tips if you think your organization might be vulnerable to a newly discovered zero day.

1. Patch your systems

Vendors and makers usually act fast to issue a patch once the zero-day vulnerability is discovered. Install it as soon as it becomes available.

2. Assess risk exposure

Identify critical third-party vendors who might be vulnerable and check if your own organization is vulnerable.

3. Update your requirements

Request additional security assurances from critical third-party vendors and update your vendor contracts accordingly.

4. Strengthen your posture

If you are a vendor to other organizations, share an update of your security posture to let them know you already conducted mitigation efforts.

5. Track, report, and conclude

Vulnerability management includes identifying, analyzing, remediating, and reporting phases; make sure everything is documented.

Why are zero days relevant to TPRM?

Dealing with unpredictable zero-day vulnerabilities is one of the greatest challenges faced by today’s security teams. They can either affect the organization directly or indirectly, through its third-party vendors with access to the network.

Log4j is a recent reminder of the impact zero-day vulnerabilities can have in entire supply chains, after it was discovered that the vulnerability could allow attackers to seize control of nearly everything from industrial control systems to web servers and consumer electronics. Until the patch was released, every organization and vendor using the open source Apache logging library Log4j was vulnerable.

This is why vendor risk assessments and continuous monitoring of your vendors' security performance are the pillars of a third-party risk management program (TPRM).

How Bitsight facilitates zero day detection & response

Bitsight third-party risk management (TPRM) is an end-to-end solution that empowers you to accelerate vendor risk assessments, continuously monitor and uncover blind spots across your digital ecosystem, and take action on exposure swiftly and confidently.

Third party risk management

Bitsight’s third-party vulnerability detection and response capabilities allow you to stay ahead of zero days and major security events, by taking action on high-priority incidents at a moment’s notice. Teams rely on these capabilities to initiate vendor outreach and track responses to critical vulnerabilities through scalable templated questionnaires — with tailored exposure evidence — for more effective remediation. 

The ability to continuously monitor your vendors’ security posture will raise timely alerts when an indicator goes beyond your security standards. In addition, a comprehensive and categorized third-party inventory will make it easier to understand where to focus your attention when a zero day occurs.

When it comes to zero day response, the ability to rapidly create and distribute a simple questionnaire among your vendors to assess exposure and manage potential threats can make the difference between business as usual and business continuity issues.

If one of your vendors is vulnerable, you can immediately ask them for additional requirements and assurances, and easily track them. You can also update their category or change their classification (i.e. more or less critical, more or less impactful for the business).

With Bitsight Vulnerability Detection & Response you can:

• Detect, manage, and mitigate emerging zero-day vulnerabilities in your vendor ecosystem with speed
• Remediate risk more quickly and effectively with better prioritization of critical vendor response
• Initiate and track vendor outreach at scale through built-in questionnaire capabilities
• Confidently adhere to growing regulatory pressure with easy access to critical vulnerability data
• Build stronger vendor relationships through timely and trusted collaboration

Threat intelligence 

The Bitsight platform leverages robust, data-driven threat intelligence and real-time monitoring, enabling organizations to rapidly detect emerging vulnerabilities within their vendor ecosystem. By proactively analyzing threat intelligence data, Bitsight allows security teams to predict potential exploitations and prioritize remediation efforts effectively, significantly reducing the risk associated with zero-day attacks.

Bitsight's threat intelligence also provides actionable insights into the security posture of vendors, highlighting specific weaknesses or unusual activity that could signal impending security incidents. This granular visibility helps organizations proactively address potential vulnerabilities before they become exploitable.

Attack surface analytics

In addition, Bitsight exposure management capabilities like Attack Surface Analytics enable you to gain continuous visibility into all of your assets – ports, endpoints, databases, applications, cloud instances, even shadow IT and remote offices – so when a vulnerability is discovered, you can act fast and drill down into the root causes of vulnerabilities.

Given this holistic view of the organization and its extended supply chain, teams can identify hidden risks and the systems or data that may be compromised if an attacker exploits a vulnerability threat.

With a complete workflow, when a new zero-day vulnerability affects your supply chain, you will be better equipped to limit the network impact and maintain control. Explore how Bitsight’s TPRM solution can help you grow and build trust across your ecosystem without worrying about expanded risk.