Third-Party Access Management

Third-party access is the attack vector organizations most consistently underestimate. In 2024, 35.5% of all data breaches traced back to a third-party compromise, and the average cost of those incidents reached $4.91 million. Third-party access management (TPAM) closes the gap between the access vendors need to do their work and the standing permissions most organizations leave in place long after that work is done. C1 automates the full vendor identity lifecycle so organizations can extend access confidently without expanding their attack surface.

Vendors, contractors, and partners require access to internal systems to deliver their services. That access is necessary. Unmanaged, it becomes one of the most exploited entry points in enterprise security. Supply chain attacks increased 68% year over year. IBM research puts the average third-party breach at $4.91 million. And 63% of organizations report they lack real-time visibility into what permissions their vendors actually hold. Regulations including HIPAA, GLBA, and frameworks like NIST all require documented controls over third-party access, making this both a security problem and a compliance obligation.

Why third-party access is high risk#

External parties are a distinct risk category because organizations extend them access without controlling their security posture. A vendor may have weak credential hygiene, share accounts across team members, or retain access indefinitely after a project closes. From the attacker's perspective, a compromised vendor credential is a trusted identity already inside the perimeter.

• Attack volume: 35.5% of 2024 data breaches involved third-party compromise
• Cost: The average third-party breach costs $4.91 million
• Credential misuse: 74% of breaches involve credential misuse, and vendor credentials are among the most abused
• Visibility gap: 63% of organizations lack real-time visibility into vendor permissions

Key technical components#

Zero trust architecture#

Zero Trust means no user or endpoint is trusted by default. Every access request is verified based on identity, device context, and policy before access is granted. For third-party access, this means vendors are not extended implicit trust because they have previously authenticated — each session is evaluated independently.

Context-aware access models#

Role-based access control (RBAC) ties permissions to defined roles, making it straightforward to apply consistent access policies across vendor types. Attribute-based access control (ABAC) adds contextual conditions: time of day, location, device posture, or task context. Combining both gives organizations precise control without creating one-off permission sets for every vendor.

Identity federation#

Identity federation connects your identity system with vendors' own identity systems using standards like SAML or OIDC. Rather than creating local accounts for every external party, federated access lets vendors authenticate through their own identity provider (IdP) while your policies govern what they can access. This eliminates orphaned local accounts and gives you a single control plane for vendor identity.

Vendor privileged access management (VPAM)#

Vendors who require elevated or administrative access represent the highest-risk subcategory of third-party access. VPAM controls include credential vaulting, session recording, automated credential rotation, and check-out/check-in workflows. See the vendor privileged access guide for full treatment of these controls.

Managing the third-party identity lifecycle#

Phase 1: Onboarding (Joiner)#

• Identity verification: Confirm vendor identity and role before granting any access
• Scope definition: Grant access only to the specific systems required for the engagement
• Least privilege: Apply the minimum permissions needed for the stated work
• Access record: Document what was granted, who approved it, and when it expires

Phase 2: Operational management (Mover)#

• Right-sizing access: When vendor scope changes, update permissions immediately
• Documentation currency: Keep ownership records current — every vendor access grant should have a named internal owner
• Periodic review: Schedule access reviews at defined intervals; monthly or quarterly for high-risk vendors

Phase 3: Offboarding (Leaver)#

Offboarding is where most organizations fail. Revocation must cover every access type: VPN credentials, SaaS accounts, API keys, shared credentials, and physical access badges.

• Trigger definition: Define what events trigger offboarding: contract end date, project completion, or personnel change on the vendor side
• Comprehensive revocation: Revoke all access types simultaneously — automation is required at scale
• Validation: Confirm revocation is complete by spot-checking accounts in target systems
• Audit logging: Log the revocation event, timestamp, and executor — required for HIPAA and GLBA compliance

Why just-in-time access is the future of vendor access#

Zero standing privilege is the principle that no identity should hold persistent access it is not actively using. Just-in-time (JIT) access operationalizes this: vendors request access when they need it, receive a time-limited grant scoped to the specific task, and access is automatically revoked when the session ends. Only 1% of companies have fully implemented JIT access. 91% acknowledge that at least half of their privileged access is persistent. With 74% of breaches involving credential misuse, persistent vendor credentials are a standing invitation for attackers.

Best practices for third-party access management#

1. Centralize the identity inventory. Maintain a single record of every vendor identity: who they are, which systems they access, when access was granted and when it expires, who internally owns the relationship, and what access level was approved.
2. Enforce least privilege by default. Start every vendor engagement with the minimum access required. It's operationally easier to expand access on request than to claw back permissions that have already been granted.
3. Mandate MFA and identity federation. Require MFA for all vendor access. Where possible, federate vendor identity through your IdP rather than creating local accounts.
4. Automate offboarding. Automation should trigger on contract end dates, personnel changes, and project completions — revoking accounts, disabling credentials, deleting API keys, and logging the revocation event without human action at each step.
5. Log everything for audit readiness. Every access grant, modification, and revocation should produce a log entry. SOC 2, ISO 27001, and HIPAA all require demonstrable audit trails for third-party access.

How C1 secures third-party access#

• Just-in-time access for vendors: Replaces standing vendor privileges with temporary, task-scoped access that revokes automatically when the session ends or the time window expires
• Full lifecycle automation: Handles provisioning, mid-engagement access adjustments, and deprovisioning without manual intervention at each step
• Unified Identity Graph: Maps every vendor identity to every permission they hold across every connected system — a single query rather than a manual audit across disconnected systems
• Self-service access requests: Vendors and internal owners can request, approve, and manage access through Slack, a web portal, or CLI
• 300+ out-of-the-box connectors: Consistent policy enforcement across the entire access surface without custom integrations for every target system
• Built-in compliance support: Access reviews and audit logging designed to satisfy third-party access control requirements in SOC 2, ISO 27001, HIPAA, and GLBA

For organizations managing non-employee access more broadly, see the non-employee access management guide and the vendor access management guide. Learn more about C1's approach to identity governance best practices and IGA success metrics.