Treat them as trusted execution paths only after they have been vetted for page access, token handling, and secret-creation permissions. If they can act inside authenticated sessions, they need governance comparable to other privileged pathways, including review, logging, and immediate revocation access.
What security teams should verify before treating extensions or skills as trusted execution paths
Extensions and agent skills are not just convenience layers when they can mint credentials or operate inside authenticated sessions. They become part of the trust boundary, which means teams should verify what they can read, what they can create, and whether any secret material can be exposed, copied, or reused outside the intended workflow.
The practical test is simple: if the extension or skill can influence authentication, token issuance, session state, or secret creation, it needs governance like any other privileged path. That includes explicit approval for the permissions it requests, clear ownership, and a plan for rapid revocation if its behavior changes or its supply chain is compromised.
Why token handling and secret-creation permissions change the control model
Once a tool can handle tokens or create credentials, it is no longer a passive helper. It can extend the lifetime of access, widen the blast radius of a compromise, or create a new credential store that defenders must inventory and monitor. That is especially important when the tool can act on behalf of a user or inside a session that already has trust.
Security teams should distinguish between read-only assistance and any capability that creates, exports, refreshes, or reuses credentials. A skill that only formats content is one thing; a skill that can provision an API key, inject a secret into a workflow, or copy an access token into a prompt is materially different because it changes the access path, not just the user experience.
When that boundary is crossed, ordinary extension review is not enough. Teams need to assess whether the extension or skill inherits page access, whether it can reach sensitive browser state, and whether its actions are logged with enough detail to support investigation and rollback.
How to govern these paths without breaking the workflow
Governance should focus on the smallest set of permissions that still lets the extension or skill do its job. Treat credential creation as a separate privilege from content access, and treat session access as separate again. If the tool needs both, it should be because the use case clearly requires it, not because the integration makes it easy.
That also means defining revocation as an operational control, not an afterthought. If a skill can create or touch credentials, security teams should know how quickly that access can be disabled, how existing credentials are invalidated, and who is responsible for confirming that downstream systems no longer trust them. For identity-centric readers, API key management guidance and secrets management guidance are directly relevant because the same lifecycle and revocation discipline applies here.
Review and logging should be designed for traceability, not just visibility. Teams should be able to answer which extension or skill requested a credential, what scope it received, whether it was created in a human session or an automated one, and whether the resulting secret was ever exported or reused. If that cannot be reconstructed, the path is not governed well enough to trust.
What breaks first when these controls are missing
The first failure is usually over-authorization. A skill that seems harmless during evaluation can become a credential factory once it is deployed broadly, especially if permissions were copied from a higher-trust use case. The second failure is poor offboarding, where a forgotten extension or retained skill keeps creating credentials long after the original approval context has changed.
Another common issue is hidden reuse. If the same extension or skill can run across multiple authenticated contexts, a single weak control can affect many sessions at once. That is why credential rotation challenges matter here: once tools begin minting or consuming credentials, lifecycle management becomes the control that limits long-lived exposure.
Security teams should also watch for token handling mistakes inside the extension or skill itself. If the path can read, cache, or forward tokens, then compromise of the extension runtime can become compromise of the authenticated account. That is a different risk profile from a normal plugin, because the tool is now inside the trust envelope that protects sessions and secrets.
Risk and Threat Considerations
Extensions and skills that can create credentials concentrate privilege in places teams often review lightly. If a malicious update, compromised extension, or overbroad skill gains access to authenticated sessions, it can mint new secrets, extend access, or move laterally without needing to steal the original user password.
Failure mechanism: The control fails when page access, session access, and secret-creation permissions are bundled together, or when created credentials are not logged, scoped, or revoked quickly enough to contain misuse.
Impact: A single compromised extension or skill can create durable access paths, bypass normal approval controls, and turn one trusted session into repeated unauthorized access until the generated credentials are discovered and invalidated.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
OWASP Non-Human Identity Top 10 and OWASP Agentic AI Top 10 address the attack and risk surface, while NIST SP 800-53 Rev 5 sets the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Non-Human Identity Top 10 | NHI-02 — Secret Leakage | Extensions or skills that create credentials can expose secrets and tokens. |
| NHI-04 — Insecure Authentication | Session-handling extensions and skills can weaken authentication trust boundaries. | |
| NHI-05 — Overprivileged NHI | Credential-creating tools need least privilege and narrow authority. | |
| Recommendation — Restrict secret handling and scan extension or skill paths for credential leakage. Verify that authentication flows and session use remain bounded and auditable. Reduce permissions so tools can only create credentials they strictly need. | ||
| OWASP Agentic AI Top 10 | ASI03 — Identity & Privilege Abuse | Skills acting inside sessions can abuse delegated authority or excessive privilege. |
| Recommendation — Constrain delegated authority and review every privilege-bearing action. | ||
| NIST SP 800-53 Rev 5 | IA-5 — Authenticator Management | Credential creation, storage, rotation and revocation are central here. |
| AU-2 — Event Logging | Teams need logs for credential creation and session actions by extensions or skills. | |
| Recommendation — Manage generated credentials with lifecycle controls and prompt revocation. Log credential issuance and privileged extension actions for traceability. | ||
Practitioner Guidance
What to verify: Confirm whether the extension or skill can read session state, create secrets, or impersonate the user in downstream systems. If it can do more than its business function requires, reduce scope before rollout.
Decision rule: If the tool can create credentials or act inside an authenticated session, treat it as privileged software and require the same review standard you would apply to other credential-bearing automation.
What good looks like: Each credential-creating action is attributable to a specific extension or skill, session boundaries are preserved, and revocation actually removes future trust rather than just disabling a user interface.
Practitioner takeaway: The real control question is not whether the extension or skill is useful, but whether it can create or extend access in ways defenders can still see, scope, and revoke quickly.