Most SaaS breaches don’t start with malware.
They start with someone clicking “Allow” on an integration prompt… and unknowingly granting a third-party app access to email, files, contacts, or an entire tenant.
That’s why SaaS Integration Vetting matters. If your business uses Microsoft 365, Google Workspace, CRMs, accounting apps, ticketing tools, and automation platforms, integrations are the “hidden network” connecting everything—often with more access than you realize.
In this guide, we’ll walk through a smarter, repeatable SaaS Integration Vetting process you can use before connecting any app. If you want a security-first partner to help standardize these reviews across your environment, start with our Solutions page or reach out via Contact Us.
SaaS Integration Vetting: Why SaaS Integrations Are a Hidden Security Risk
Integrations feel harmless because they’re “just workflow.” But in practice, they can become a permanent access path to sensitive data. The most common risks we see from poor SaaS Integration Vetting include:
- Permission sprawl: apps request broad scopes “to make setup easier,” and they rarely get reduced later.
- Shadow integrations: users connect tools without IT/security review.
- OAuth token persistence: access continues even after a user leaves or stops using the tool.
- Unsafe consumption: trusting data returned by third-party APIs more than you should.
- No lifecycle management: no owner, no documentation, no periodic review, no clean offboarding.
OWASP calls out “Unsafe Consumption of APIs” as a major risk category because attackers often target integrated third-party services as a path into your environment. OWASP API Security Top 10 (2023)
What You Should Know Before Connecting Any App
Before you approve any integration, pause and answer three questions. This is the start of good SaaS Integration Vetting:
- What data does it touch? Email, files, contacts, calendars, customer data, payment data, HR data, legal documents?
- Where does the data flow? Which systems send data out, and where is it stored?
- Who is allowed to authorize it? Any user, or admins only? Can users grant organization-wide access?
If you can’t confidently answer those questions, the integration shouldn’t be approved yet.
Step 1: Identify the Integration Type
SaaS Integration Vetting starts by identifying how the integration authenticates. Most integrations fall into a few common buckets:
OAuth (Delegated or Application Permissions)
OAuth-based integrations may request access on behalf of a user (delegated) or access without a user (application permissions). Understanding the difference matters because some permissions can grant much broader access across the organization. Microsoft’s overview is excellent if you’re in an Entra/Microsoft 365 environment: Permissions and consent overview (Microsoft identity platform)
API Keys
API keys can be simple and powerful—sometimes too powerful. If an API key is leaked, it can become a long-lived access path unless you rotate and revoke effectively.
Webhooks and Service Accounts
Webhooks can introduce data-exfil paths. Service accounts can become “immortal users” if they aren’t governed like humans (ownership, MFA where possible, scope, and expiration).
Before you move on, document the integration type. This single step improves SaaS Integration Vetting consistency.
Step 2: Review Permissions and Scope
This is the most important part of SaaS Integration Vetting: permissions determine blast radius.
When you review permissions, look for:
- Read vs. write: Write permissions often allow data manipulation, not just viewing.
- All users vs. single user: Organization-wide scopes are much riskier than scoped, user-specific access.
- Mail, files, and directory access: These are high-impact categories in most businesses.
- Offline access / refresh tokens: This can extend access beyond a single session.
Best practice is least privilege: approve only what the integration must have. If the vendor “requires” broad access for convenience, treat that as a risk signal during SaaS Integration Vetting.
Step 3: Validate Vendor Security Posture
SaaS Integration Vetting isn’t only about permissions. It’s also about who you’re trusting with your data.
Minimum vendor checks:
- Security documentation: Do they provide a security page and clear contact path?
- Third-party attestations: SOC 2 Type II or ISO 27001 are common signals (not perfect, but useful).
- Data handling clarity: Do they disclose subprocessors and data storage regions?
- Incident transparency: Do they publish advisories and timelines?
You don’t need to become a compliance auditor. You do need enough confidence that the vendor treats security as a core function—especially if the integration touches email, files, or customer data.
Step 4: Confirm Data Handling and Retention
Integrations can copy data out of your primary platforms. Good SaaS Integration Vetting includes retention questions:
- What data is stored? And is it stored at rest encrypted?
- How long is it retained? Is retention configurable?
- How do you delete it? Can you request deletion and verify completion?
- Can you export logs? Can you see what the integration accessed and when?
If the vendor can’t explain retention and deletion clearly, treat that as a red flag.
Step 5: Lock Down Who Can Authorize Integrations
In many environments, the biggest gap is that any user can authorize an app. If you’re a Microsoft 365 shop, tightening consent settings is a high-impact SaaS Integration Vetting control.
Microsoft provides guidance to restrict user consent and reduce the risk of malicious apps tricking users into granting access. Configure how users consent to applications (Microsoft Entra)
Practical policy options:
- Allow user consent only for verified publishers and low-risk permissions.
- Disable user consent and require admin approval for integrations.
- Require users to request approval (admin consent workflow) instead of self-approving.
This step alone reduces the number of “shadow integrations” and makes SaaS Integration Vetting enforceable, not optional.
Step 6: Add Monitoring and Offboarding Rules
Integrations are not “set and forget.” Mature SaaS Integration Vetting includes ongoing governance:
Monitor for new integrations and permission changes
- Alert when new enterprise apps are added
- Alert when permissions expand
- Review sign-in logs and unusual app activity
Offboard integrations when tools are retired
- Remove the integration
- Revoke tokens/keys
- Remove service accounts
- Rotate secrets that may have been exposed
- Document the retirement
If you want always-on visibility into suspicious activity across endpoints and accounts, MDR can help—see our Managed Detection and Response overview.
Common Mistakes When Vetting SaaS Integrations
These are the patterns that consistently lead to preventable exposure:
- Approving based on convenience: “We need it today” becomes “We forgot it existed.”
- No documentation: Nobody knows what the integration does or who owns it.
- No periodic review: Permissions creep is real.
- Overbroad scopes: Accepting “read all mail” or “read all files” without a strong reason.
- No consent governance: Letting any user authorize apps undermines SaaS Integration Vetting entirely.
If you’re building a more structured security-first IT posture, you can learn more about our approach on our About page or browse industries we support via Who We Serve.
SaaS Integration Vetting Checklist
Use this SaaS Integration Vetting checklist before approving any integration.
15-minute quick screen
- What system is being connected, and what data is involved?
- What integration type is used (OAuth, API key, webhook, service account)?
- What permissions are requested (read/write/admin, org-wide vs scoped)?
- Who is the vendor and what security posture signals are available?
- Who owns this integration internally?
Full review (recommended for high-risk apps)
- Verify least-privilege permissions and reject unnecessary scopes
- Confirm retention, deletion, and subprocessors
- Confirm logging and export capabilities
- Enforce admin approval workflow for new integrations
- Create an offboarding plan (revoke tokens/keys, remove accounts, rotate secrets)
- Schedule periodic review (quarterly for most orgs; monthly for high-risk)
If you want help turning this into a standardized internal policy and process, the simplest next step is a quick discovery call via Contact Us. For common questions about how we support SMB environments, you can also review our FAQ.
FAQ
What is SaaS Integration Vetting?
SaaS Integration Vetting is the process of reviewing an app integration’s authentication method, permissions, vendor security posture, data handling, and ongoing governance before connecting it to business systems.
What’s the biggest risk with OAuth-based integrations?
OAuth integrations can request broad delegated or application permissions. If over-scoped or approved without review, they can create a long-lived access path to email, files, and tenant data. A good starting reference is Microsoft’s permissions and consent overview.
Should users be allowed to approve SaaS integrations themselves?
In many organizations, limiting or disabling user consent reduces risk and prevents shadow integrations. Microsoft provides guidance on configuring user consent controls in Entra here: configure user consent.
How often should we review existing integrations?
At minimum, quarterly. Review more frequently for high-risk integrations that touch email, file storage, customer data, finance, HR, or identity systems. Consistent review is part of mature SaaS Integration Vetting.
What’s a fast win to reduce integration risk?
Implement an approval workflow (admin consent) for new integrations, require least-privilege permissions, document owners, and enforce offboarding when tools are retired. That combination makes SaaS Integration Vetting repeatable and sustainable.
