The continuing surge in third-party data breaches underscores the profound cybersecurity vulnerabilities present in vendor supply chains. Case in point, Black Kite’s 2024 Third-Party Breach Report found that 92 vendors were linked to breaches impacting 227 companies.
The true impact likely extends to more than 700 organizations due to undetected supply chain weaknesses. These “silent breaches” highlight the growing risk of unseen vulnerabilities within interconnected ecosystems. The report confirms these alarming trends, particularly regarding ransomware, unauthorized access, software vulnerabilities, and credential misuse.
The good news is that cybersecurity providers who truly understand rapid incident response and post-breach remediation can provide their customers with direct insight into the tactics adversaries use to exploit third-party relationships. Those who successfully adapt to modern threat behaviors can help organizations harden their defenses against these systemic risks.
Growing Threat of Third-Party Vulnerabilities
Threat actors are increasingly exploiting systemic weaknesses within vendor supply chains to breach multiple organizations at once. The most common vulnerabilities include:
- Unsecured remote access. Exposed Remote Desktop Protocol (RDP) and Virtual Private Networks (VPNs) without multi-factor authentication (MFA) remain prime targets.
- Unpatched software and misconfigurations. Outdated systems provide attackers easy entry points.
- Overprivileged third-party access. Vendors with excessive permissions are used as steppingstones for further compromise.
- Lack of real-time monitoring. Many organizations fail to continuously audit vendor activity, allowing threats to persist undetected.
Unauthorized Network Access
Black Kite’s report found that more than 50% of publicly disclosed third-party breaches in 2024 were due to unauthorized network access. Attackers exploit weak access controls, often leveraging stolen or brute-forced credentials.
Organizations can mitigate this risk by:
- Implementing least privileged access. Vendors should only have access to what they absolutely need.
- EnEnforcing MFA. Strong authentication should be required for all vendor logins.
- Monitoring vendor activity in real-time. Suspicious login patterns and data transfers should trigger immediate investigations. Behavioral analytics can detect and respond to unauthorized access before it escalates into a full-blown breach.
- Segmenting networks. Vendors should never have unrestricted access to sensitive environments.
Ransomware and the Supply Chain
Ransomware remained one of the most disruptive cyber threats of 2024, with 66.7% of known attack methods leveraging third-party vectors, Black Kite reports. Attackers use third-party relationships to amplify ransomware attacks, primarily by:
- Compromising managed service providers (MSPs). Attackers use remote management tools to distribute ransomware across multiple clients.
- Targeting software supply chains. Malicious updates introduce backdoors that spread ransomware to unsuspecting users.
- Destroying backups. Attackers infiltrate third-party backup providers to eliminate recovery options before deploying ransomware.
To counteract these threats, organizations should implement an immutable backup strategy, ensuring they maintain secure, recoverable backups that are resistant to ransomware attacks.
Software Vulnerabilities and the Risks of Unpatched Systems
The Black Kite report reinforces that zero-day vulnerabilities and unpatched systems remain major security risks. Attackers continue to exploit weaknesses in internet-facing devices, operating systems, and widely used applications.
Organizations can reduce these risks by mandating strict patching service level agreements in vendor contracts to ensure timely updates, requiring real-time vulnerability scanning for all third-party systems, and adopting a zero-trust approach to enable continuous validation of vendor security.
I have observed an increase in Golden Security Assertion Markup Language (SAML) cyberattacks. A Golden SAML attack is a technique wherein a threat actor compromises the secret key used to sign SAML assertions. Token theft attacks stemming from software supply chain compromises are also on the rise, further emphasizing the need for continuous attack surface monitoring.
Rise of Credential Misuse
Credential misuse accounted for 8% of third-party breaches in 2024. Powering this tactic are:
- Dark web credential dumps fueling credential stuffing and brute-force attacks.
- Automated tools that make it easier for attackers to exploit stolen credentials.
- Session hijacking techniques that allow attackers to bypass authentication controls.
- To combat credential misuse, organizations must:
- Enforce phishing-resistant MFA (e.g., FIDO2 security keys).
- Implement just-in-time (JIT) access for privileged accounts.
- Monitor login anomalies to detect and block unauthorized access attempts.
- Leverage dark web monitoring to identify compromised credentials before they are used in attacks.
Why Software Supply Chains Are Under Attack
One of the most striking findings in the Black Kite report is that one in four third-party breaches last year originated with software vendors.
Attackers are increasingly targeting software supply chains because:
- A single compromise can impact hundreds of organizations simultaneously.
- Software updates are inherently trusted, making it easier to deliver malicious payloads.
- Organizations are accelerating digital transformation, increasing reliance on third-party software.
- Therefore, organizations must prioritize supply chain security validation and code integrity checks before deploying updates to mitigate this risk.
How to Prevent Costly Third-Party Breaches
Organizations cannot afford to take a passive approach to third-party security. To reduce the risk of third-party breaches, they should:
- Conduct continuous third-party risk assessments instead of relying on annual audits.
- Mandate strong security requirements in vendor contracts, including MFA, logging, and patching obligations.
- Adopt a zero-trust model, assuming all third-party access is potentially compromised.
- Enhance incident response readiness, ensuring rapid containment and recovery in case of a breach.
· As third-party breaches continue to rise, organizations must recognize that their security is only as strong as the weakest link in their vendor ecosystem. By proactively assessing vendor risks, implementing robust security controls and leveraging expert solutions, organizations can better protect themselves from the growing threat of supply chain attacks.
The era of passive vendor security is over. It’s time for a proactive, battle-ready approach to third-party risk management — one that features post-breach remediation and cutting-edge solutions for backup resilience and infrastructure hardening while delivering continuous monitoring to detect emerging threats.
