What are zombie APIs?
Zombie APIs are API endpoints that remain operational despite lacking ongoing maintenance or official support. Otherwise known as end-of-life APIs, these endpoints are assumed to be decommissioned, meaning they often lack up-to-date security measures – such as encryption, rate limiting, authentication, and logging/monitoring – or those controls are misconfigured.
Without these must-have controls, zombie APIs pose major security risks.
The lack of strong security control is a major pain point, but it doesn’t stop there. End-of-life APIs also miss out on policy updates, monitoring, and compliance guardrails, which make them a serious blind spot in the cloud. They can be ridden with vulnerabilities like misconfigurations, data exposure, broken authentication, and absent data sanitization—and no one would know. Events like the Life360 data leak show just how catastrophic API vulnerabilities can be.
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You can think of zombie APIs as related to shadow APIs, which operate outside IT and security visibility. They are also similar to orphaned APIs, which lack clear ownership. Despite subtle differences among zombie, shadow, and orphaned APIs, the risks associated with each remain equally critical to address, especially in federated cloud estates.
Our previous guide cut through the noise, helping businesses achieve an understanding of fundamental API security principles to mitigate these risks.
In this article, we’ll zero in on why cloud environments are often crawling with zombie APIs. We’ll provide actionable guidance on how to detect these hidden and urgent cloud security risks—and eradicate them once and for all.
Why zombie APIs are common in the cloud
Let's dig into why zombie APIs are all over the cloud.
The push for fast development
Cloud technologies enable accelerated application development, much of which is API-driven. In high-octane CI/CD pipelines, businesses often employ shift left methodologies, which involve embedding security early in the software lifecycle.
Done well, shift‑left can accelerate secure delivery, but it introduces trade‑offs. First up (you guessed it): zombie APIs. Why? Because platform engineers and DevSecOps teams often spin up resources ad hoc and stitch them together with APIs. The issue is that these APIs are often neglected, and at end-of-life, not all of them are securely decommissioned.
Lackluster API management
Microservice architectures, which make up most cloud-first strategies, are complex. Made up of fast-moving and ephemeral Kubernetes, containers, and serverless resources, API management is anything but straightforward.
The constant churn of cloud services and resources proliferates zombie APIs. Just like with shift left security, microservices architectures are an example of the give and take of the cloud that we so often see. They might breed zombie APIs, but they’re a key part of your cloud operations.
The new love: AI
Widespread AI adoption is another zombie API accelerator.
AI is driving value across diverse use cases, but endpoints are often spun up fast and then ignored, leading to zombie API sprawl and new security vulnerabilities. Recent data shows that AI-related API vulnerabilities experienced a 12-fold increase in 2024.
Here's the catch with zombie APIs: The same things that create them are what make the cloud so powerful in the first place. This means that cloud security teams need to walk a fine line between mitigating zombie API risks and maintaining high-performing API-driven cloud environments.
The risks posed by zombie APIs
So what makes zombie APIs so dangerous? In this section, we list the concerns and explain why they matter. And since we’re on the subject, here’s some useful information on other crucial cloud vulnerabilities like subpar access controls, poor logging and monitoring, and insider threats.
Unpatched vulnerabilities and missing security controls
Similar to shadow APIs, end-of-life APIs often operate without governance or active monitoring. That means they can be infested with vulnerabilities:
Injection flaws: APIs that lack input validation and sanitization help threat actors inject malicious commands to infiltrate your systems and exfiltrate data.
Broken authentication: Out-of-date or insufficient authentication controls weaken an API’s security posture, inadvertently allowing illegitimate users easy access.
Excessive data exposure: APIs that overshare sensitive information or metadata in their responses can spark noncompliance and data privacy incidents.
Broken object-level authorization (BOLA): The lack of object-level authorization enables adversaries to manipulate object identifiers and gain access to your sensitive data.
For a more comprehensive look at top API security risks you could encounter in your cloud, check out OWASP's ranking.
Data exposure and compliance violations
Zombie APIs are hives for non-compliance. Because these APIs are often forgotten, they operate outside the scope of regulatory guardrails, allowing risks for sensitive data exposure to escalate unchecked.
The consequences of a zombie API depend on your sector: One that exposes healthcare data can mean violating HIPAA requirements, one that handles payment information can lead to breaching PCI DSS, and an API entrusted with EU citizen data can land you in violation of GDPR.
With zombie APIs, the problem isn't just that they weaken a business's data security posture; it's that it's nearly impossible to inventory or document the data they expose. Without documentation, it’s difficult for security teams to assess risk, let alone comply with regulatory requirements.
Attack path and lateral movement enablement
End-of-life APIs are ideal footholds for malicious actors. Adversaries can conduct advanced persistent threat attacks by hijacking one and using it as a vector.
Zombie API vulnerabilities, like excessive access privileges and data exposure, allow threat actors to modify them into weapons.
With lax security protocols and insufficient monitoring and logging, end-of-life APIs create hidden paths to sensitive data and business-critical resources. Find one zombie API, and boom—attackers can potentially hop across your entire cloud setup.
Want to know more about analyzing attack paths? We explain all about it here.
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How to mitigate zombie API risks?
Here's how you can tackle zombie API risks and vulnerabilities.
Automated discovery and inventory management
Set up automation-driven mechanisms to ensure continuous discovery and inventorying of APIs. And yes, that includes even zombie and shadow APIs that were accidentally forgotten.
Another tip? Use runtime traffic analysis, API gateway logs (e.g., Amazon API Gateway, Azure API Management, Apigee), and cloud service discovery tools.
To identify specification drift and end-of-life APIs, study the gaps between OpenAPI specifications and actual deployed endpoints. If you need extra support, take a look at our list of OSS API security tools, including Hurl, Kong Insomnia, and SoapUI.
Code-to-cloud mapping and source analysis
Use static code analysis to identify API endpoints defined in source code but not properly documented or maintained. Trace cloud resources back to their source code repositories to identify ownership and maintenance status.
And don’t forget to scan your container images – they can reveal open ports, exposed services, and vulnerable packages, but application routes/endpoints are best identified via code analysis and runtime traffic.
What’s the key to finding zombie APIs? Correlate your infrastructure-as-code definitions with the resources you’ve deployed. To support this step, you need a rock-solid ASPM solution that transcends traditional AppSec approaches.
Behavioral analysis and anomaly detection
Advanced ML models help you uncover unusual API usage patterns to identify zombie API exploitation. But keep things simple: First, establish baseline traffic patterns. Then, keep an eye out for deviations.
To detect endpoints that are being accessed without proper credential validation, look for suspicious authentication patterns, and set up alerts. Create triggers to alert when API endpoints receive traffic but show no recent security or maintenance updates (e.g., no recent commits, scans, or deployments) – a major red flag.
API lifecycle governance and deprecation workflows
Establish formal API versioning strategies that include clear deprecation timelines and sunset dates; this will reinforce your entire API lifecycle governance posture. Set up automated processes that prevent new API deployments without proper documentation or ownership assignment.
Also set up mandatory deprecation workflows that require explicit approval and monitoring before endpoints can be decommissioned.
Remember: Developing API retirement checklists helps ensure proper security assessments, data migration, and stakeholder notification.
Want to prevent zombie APIs in the first place instead of hunting them down later? Check out these tips.
Embedded developer-centric security
Incorporate API scanning into your CI/CD pipelines to identify risk-ridden zombie APIs before they sneak into production. IDE plugins and pull request automation can help developers avoid creating undocumented endpoints.
Be aggressive with security guardrails: Set up controls to stop deployments of APIs that lack authentication, monitoring, or documentation. To spread the message organization-wide, create developer training programs that emphasize secure API lifecycle management as part of cloud-native development practices.
Continuous monitoring and maintenance
Round-the-clock surveillance is a must for revealing zombie APIs and preventing current APIs from being forgotten. So make sure to install runtime API discovery tools that continuously monitor for new, changed, or end-of-life endpoints.
And don’t forget to automate! Automated compliance is non-negotiable to flag APIs that expose sensitive data. Establish regular API inventory audits to verify that all discovered endpoints have assigned owners and maintenance schedules, and create incident response procedures specifically for zombie API discovery and emergency remediation.
How Wiz secures your API landscape from code to cloud
Zombie APIs constitute a critical blind spot in contemporary cloud setups. They’re hard to detect, often overlooked, and rarely covered or contextualized by traditional tools.
There’s only one way to solve the zombie API crisis for good: Get a holistic cloud security solution that views APIs as part of a larger security fabric—not an isolated issue. Which brings us to Wiz.
Wiz mitigates risks associated with zombie APIs via end‑to‑end visibility (from code to runtime), combining agentless cloud context with the Wiz Runtime Sensor for API discovery today, and correlating findings in the Wiz Security Graph to expose true attack paths and owner assignments.
To reinforce shift left, Wiz Code unifies security with developer workflows, scanning for API-related vulnerabilities in code and IaC templates before they’re deployed. And with Wiz Security Graph you get comprehensive coverage, mapping connections across code repos, pipelines, and runtime.
Most importantly, Wiz always focuses on real exploitability and business risk. What does that mean from a zombie API standpoint? Wiz doesn’t diagnose or analyze end-of-life APIs in isolation. Instead, Wiz ties them to real risks and measures them based on actual business criticality.
Ready to eliminate API blind spots? See how Wiz turns zombie API detection into real‑world risk reduction.
