Third Party Risk

What third party risk means in practice

Third party risk is not just “vendor risk” in the narrow procurement sense. It is the exposure created when an outside party can reach your data, systems, workflows, or trust relationships, and it becomes materially worse when that access is persistent, poorly scoped, or hard to revoke.

In security programmes, the term usually spans suppliers, contractors, outsourcers, SaaS providers, integrators, and platforms that sit inside business-critical processes. The important question is not whether the third party is trusted in principle, but whether that trust is bounded, monitored, and reversible.

This is why third party risk often shows up through integrations, delegated administration, API access, shared credentials, and data-sharing arrangements rather than through a direct compromise of your own perimeter.

Why third party relationships create security exposure

The main danger is that a weakness outside your organisation can become an entry point inside it. If a supplier account, token, certificate, or integration is abused, the attacker may inherit legitimate access paths that bypass normal user controls and make the activity look routine.

That makes third party relationships attractive for credential theft, business email compromise, data theft, and downstream lateral movement. A vendor can also expand your attack surface simply by storing, processing, or relaying sensitive information on your behalf.

For examples of how this plays out in real incidents, see Slack GitHub breach 2022, GitHub OAuth token breach 2022, and Mimecast certificate compromise 2021, all of which show how trusted third party access can be turned into real exposure.

How organisations assess exposure to third party risk

Assessment starts with a complete inventory of who has access, what they can reach, and which business processes depend on them. That includes SaaS integrations, API connections, support channels, service accounts, remote support tools, and any shared or delegated credentials.

From there, organisations should check whether the third party is internet-exposed, whether the integration is business-critical, and whether the relationship is still necessary. Vendor assurances matter, but they do not replace verification of actual data flows, privilege levels, and revocation paths.

External references such as EU Digital Operational Resilience Act (DORA) and SOC 2 Trust Services Criteria (AICPA) are useful here because they frame third party oversight as a governance and assurance problem, not just a checklist exercise.

Reducing third party risk without breaking business operations

The practical aim is to narrow trust to the minimum that the business actually needs. That usually means limiting privileges, separating environments, time-bounding access where possible, and preferring revocable, monitored integrations over long-lived standing access.

Where sensitive data or production systems are involved, organisations also need clear offboarding and rotation discipline. If a vendor relationship ends, or if a third party credential is suspected to be exposed, the access path must be removed quickly and completely, including downstream tokens and connected applications.

For supply-chain and integration-heavy environments, OWASP Non-Human Identity Top 10, SLSA, and NIST SSDF (SP 800-218) are useful because they emphasise provenance, credential hygiene, and supply-chain integrity.

What to investigate after a third party compromise

When a third party is compromised, the first question is whether the attacker touched your environment through the trust relationship. The next question is what data, sessions, secrets, or administrative paths were exposed, because third party incidents often spread through valid authentication rather than obvious malware.

Post-incident review should include token revocation, certificate rotation, log review for unusual use of vendor access, and checks for persistence in connected systems. If the third party had access to support portals, CI/CD tools, identity providers, or customer-facing workflows, those touchpoints deserve immediate scrutiny.

Incident patterns such as BeyondTrust breach 2024, JumpCloud breach 2023, and Palo Alto Networks Salesforce data theft 2025 show why compromise review must extend beyond the vendor and into the connected trust chain.

Related resources from NHI Mgmt Group

• How do third-party SaaS integrations create NHI risk and how should they be managed?
• How can IAM and security teams reduce third-party risk from AI-enabled SaaS tools?
• How can organisations reduce risk from third-party OAuth integrations?
• What is the difference between third-party risk management and NHI governance?