From Discovery to Defense: Building a Mature API Security Program for CISOs
This webinar, hosted by Tim Erlin of Wallarm with insights from Graham Ludlow (HPE) and Ken Foster (Candescent), examines API security through a CISO’s lens. The session connects technology and business trends to concrete security requirements, highlighting where traditional controls fall short and how to build a resilient API program.
Why it matters: APIs are now the backbone of digital operations, AI integrations, and partner ecosystems. Their speed and ubiquity amplify business value—and risk. For IT and security leaders, aligning API protection with business logic, non-human identities, and third-party dependencies is now a core responsibility.
API Security in Context: What’s Driving the Risk
Digital and AI transformation expand attack surface
Enterprises have matured through digital transformation and now accelerate into AI-enabled operations. Both phases are API-intensive—modernizing integrations, enabling real-time services, and connecting to third parties. As Ludlow notes, even “non-software companies” now depend on APIs throughout their value chain. That ubiquity increases exposure: public, private, partner, and AI-facing APIs all become control points.
Velocity, complexity, and shadow ecosystems
Speed is the business mandate—batch jobs give way to real-time interactions. Foster highlights the proliferation of shadow APIs and now “shadow AI,” echoing past shadow IT patterns. The net effect is reduced visibility and accelerating risk if governance, inventory, and monitoring do not keep pace.
The Modern API Threat Landscape
Two primary risks: extortion and exposure
Ludlow frames threats in two buckets. First, malicious actors exploit APIs for disruption and extortion—denial of service at the endpoint (not just volumetric DDoS) and business logic abuse that can degrade operations. Second, inadvertent data exposure via misconfigured or overly permissive APIs triggers regulatory violations and privacy incidents—even without an “attack.”
AI-driven misuse and non-human identities
AI agents operate through APIs. That shifts problems from authentication to authorization: can you bind each API call’s scope to the initiating prompt and policy? Least privilege for agents, strong entitlement governance, and runtime monitoring become critical to prevent overreach and data leakage.
Lessons from Recent Incidents
AI chatbots, hiring data, and business logic gaps
In incidents involving Paradox AI/McDonald’s and Restaurant Brands International (RBI), researchers demonstrated how AI-assisted interactions and open or weakly validated APIs expose sensitive data or operational artifacts (e.g., drive-thru recordings used for analytics). Takeaway: security must validate intent vs. design—“using the API as designed, not as intended” enables business logic abuse. Traditional controls alone do not prevent these failure modes.
Payments abuse: when attackers want money, not data
The FlexPay case underscores that attackers often target direct financial outcomes. APIs that trigger payouts, credits, or irreversible actions require heightened authorization, rate limits aligned with business norms, and behavior-based anomaly detection.
From Maturity to Execution: Building an API Security Program
Start with policy, education, and governance
Ludlow advises beginning with policy and training across developers, IT, and business teams. Establish expectations for API design, data handling, and third-party usage. Then enforce through governance—embedding security in processes and automating checks as maturity grows.
Inventory and posture first
Discovery is foundational: maintain a real-time catalog of internal, partner, and COTS-exposed APIs. Add context—data classification, exposure (internet-facing vs. internal), auth method, business owner, expected rates/seasonality. Treat APIs as first-class assets/entities in your CMDB and risk registers.
Program Requirements by Function
Discover (and manage posture)
- Automated discovery across internal and external surfaces, including third-party and product APIs.
- Data-aware classification (PII/PCI/regulated), exposure level, and owner mapping.
- Tie to third-party risk: require partners to document business flows, expected rates, and controls.
Protect (prevent and detect)
- Strong authN/authZ for human and non-human identities; enforce least privilege and token scopes.
- Gateway/WAF plus API-specific runtime protection for injection, abuse, and anomaly detection.
- Business logic and behavior-based controls, informed by baselined volumes, bursts, and seasonality.
- Lifecycle hygiene: versioning, deprecation, and blocking stale endpoints.
Respond (prepare for API-specific incidents)
- Incorporate API scenarios into IR plans; practice playbooks and escalation for revenue-impacting endpoints.
- Ensure real-time observability: logs, request metadata, client/agent attribution, IP intelligence.
- Define authority to throttle or disable endpoints and pre-approve containment actions to avoid hesitation.
Test (shift-left and validate in runtime)
- Integrate API security testing into CI/CD; include business logic, fuzzing, and negative tests.
- Mirror production-level controls and data patterns in lower environments to avoid rollbacks that reintroduce risk.
- Continuously test runtime protections and alert fidelity.
Key Takeaways
- Treat APIs as assets/entities: maintain a live inventory with data classification, exposure, and ownership.
- Pair strong authZ for non-human identities with runtime detection for business logic abuse.
- Codify API-specific incident response, including who can throttle or shut down revenue APIs.
- Integrate API security into CI/CD and test against business logic, not just protocol exploits.
- Extend discovery and governance to third-party and product APIs; align rate limits to real business patterns.
Conclusion
API security is now a core competency for IT and security leaders, spanning digital, AI, and partner ecosystems. As the perimeter shifts to endpoint logic and machine-driven access, programs must evolve from generic controls to intent-aware authorization, runtime protection, and business-aligned monitoring. For CISOs, the path forward blends policy, posture management, and automation with pragmatic incident readiness—ensuring APIs enable growth without compromising resilience.
