7 Attack Surface Reduction Rules to Implement Today

You’re not imagining it: your attack surface is expanding faster than you can keep up. Every new cloud service, API, or open-source package adds another potential entry point. And while engineering velocity keeps accelerating, security teams are stuck playing whack-a-mole with misconfigurations, exposed credentials, and forgotten infrastructure.

There’s no more “low-risk” posture when 10% of attack paths require three steps or fewer to exploit. Your CI pipeline, your forgotten S3 bucket, and that one overly permissive service account are all part of the story. This isn’t sustainable.

Attack Surface Reduction (ASR) is how you stop playing defense and start building hardened systems by default. It helps you remove unnecessary exposure, automate policies, and give your team the tools to move fast without creating new risks.

What Does Attack Surface Reduction (ASR) Mean?

Attack Surface Reduction (ASR) is a set of policies and actions that minimize the number of potential entry points an attacker could exploit in a software environment. Your attack surface is every potential entry point an attacker could exploit across code, cloud, third-party tools, and infrastructure. Modern software environments include:

• Misconfigured cloud resources and over-permissive IAM roles

• CI/CD pipelines with secrets or exposed artifacts

• Public APIs and unvetted open-source dependencies

• Infrastructure-as-code that replicates insecure defaults

As systems scale, so does the risk. Attack Surface Reduction helps you manage attack surfaces sustainably. It embeds security posture directly into dev workflows, removing unnecessary items, hardening what remains, and continuously validating configurations. For example, following this approach, you may:

• Kill unused APIs and decommission forgotten cloud resources

• Strip excessive permissions from infrastructure and service accounts

• Validate software bill of materials (SBOMs) to avoid dependency risks.

While Microsoft’s ASR rules (like blocking macro execution or restricting Office behavior) are widely implemented on endpoints, cloud-native and DevSecOps teams need broader controls across infrastructure and pipelines.



The Key Benefits of Implementing Attack Surface Reduction Rules

1. Prevention of Exploits and Malware

ASR rules block execution paths that attackers typically rely on. This means turning off high-risk behaviors that attackers often use in initial compromise on endpoints. In cloud environments, ASR logic translates to enforcing image scans in CI pipelines, restricting privilege escalation actions, and requiring signed commits or SBOM validation.

2. Reduced Risk of Lateral Movement

Attackers who land on your system often try to move laterally—pivoting to adjacent services or privilege escalation paths. ASR rules constrain this by minimizing overexposed credentials, reducing the blast radius of compromised users or workloads, and enforcing strong isolation, such as subnet segmentation or role-based access in CI systems. 

3. Real-Time Protection Against Phishing

ASR policies like URL and content scanning in email and browser sessions reduce exposure to phishing-based credential theft. For dev teams, that means enforcing SSO, MFA, and detection for token exposure (like AWS keys in Git commits) to stop credential-based compromise before it starts.

4. Standardized Policies

Many vulnerabilities stem from default settings like open ports, permissive ACLs, and default credentials. ASR policies help standardize hardened templates and IaC security baselines, ensuring devs don’t accidentally reintroduce insecure configurations. It shifts security from tribal knowledge to codified enforcement.

5. Scalable, Policy-Driven Security

ASR lets you embed security into code and infrastructure pipelines, enforcing policies automatically as part of development. By shifting to policy-as-code, misconfigurations are blocked before reaching production. This approach scales with your infrastructure, not your team. It delivers consistent, automated security without adding operational overhead.



7 Attack Surface Reduction Rules to Implement Today

1. Automate Security Testing in CI/CD

You can’t reduce your attack surface if you don’t have complete visibility into what’s being shipped. Embedding security checks into your CI/CD pipeline is the only scalable way to catch misconfigurations, insecure code, and dependency issues before they hit production. Reducing attack surface involves:

• Static analysis: can catch unsafe patterns, such as tainted input reaching dangerous functions or logic bugs that lead to authorization bypasses.

• Dependency scanning should include direct and transitive dependencies, especially base container images, flag known vulnerabilities, and enforce build-time policies.

• Secrets detection: should run locally and in CI pipelines to catch hardcoded credentials, API tokens, and sensitive strings before code ships.

To go a step further, continuous penetration testing can simulate real-world attacker behavior across your evolving codebase and infrastructure, providing dynamic insights that complement static and signature-based scanning.

The key is to treat security scans like test coverage: blocking deploys on critical issues while allowing flexibility on informational findings. Jit’s Product Security Platform orchestrates multiple scanners—covering code, IaC, dependencies, and secrets—into a single, developer-first workflow. The platform lets you define and enforce policies as code, version them alongside your app, and apply them consistently across CI/CD. 

2. Remove Unused and Exposed APIs

Old, undocumented, or internal-only APIs are still part of your attack surface. These often lack auth, rate limits or leak sensitive data through mechanisms like GraphQL introspection.

Start by auditing your APIs and removing anything unused. Attack surface management tools can help automatically discover exposed endpoints, including forgotten routes, legacy APIs, or internal tools unintentionally left accessible.

Document, authenticate, and monitor all active endpoints. Route all traffic through an API gateway to enforce consistent policies like authentication, rate limiting, and request inspection. And don’t just forget old versions—deprecate them deliberately and track for unexpected traffic. If it’s still reachable, it’s still part of your attack surface.

3. Harden Cloud Configurations and IAM

Misconfigurations remain one of the most common breach vectors. That’s not because people are careless—it’s because cloud IAM is dense, sprawling, and often undocumented. Start with the least privilege and build upward. For example, replace wildcards like s3:* with the smallest required actions. Use deny-by-default and service control policies (SCPs) and rotate temporary credentials and API keys using short-lived tokens.

Then, codify your guardrails. Use IaC scanners to detect overly permissive policies at the PR level, and implement drift detection to identify when infrastructure diverges from its secure baseline.

4. Continuously Monitor for Shadow IT and Rogue Assets

Shadow IT includes anything provisioned outside formal processes: test environments spun up and forgotten, third-party tools with OAuth access, or even personal SaaS accounts connected to corporate email. These rogue assets are risky because they often bypass hardening steps and security reviews. Exposed subdomains or infrastructure linked to staging environments or feature branches can be discoverable and exploitable by threat actors. 

Use external asset discovery to monitor your actual perimeter. Monitoring DNS records for dangling subdomains and identifying SaaS sprawl using OAuth inventories or Cloud Access Security Brokers (CASBs) is also essential. Internally, teams should log and verify new service creation across cloud providers to avoid untracked assets slipping through. 



5. Secure Dependencies and Enforce SBOM Hygiene

Every third-party integration introduces hundreds of indirect dependencies, many with unknown risks. Managing this means applying the same rigor to third-party code as your own.

• Generate and validate SBOMs as part of your build process. 

• Integrate real-time CVE scanning into CI and set enforcement policies tied to severity, EPSS scores, or exploit maturity.

• Pin versions and validate cryptographic checksums in all package managers.

• Automate dependency updates but gate them behind CI test suites and vulnerability diffing to prevent breaking changes or regression reintroductions.

• Continuously audit dependency trees. Flag libraries that are outdated, unmaintained, or pull in high-risk transitive packages.

6. Enforce Secure Code Practices from Day One

The earlier you catch a vulnerability, the cheaper it is to fix, so shift security as far left as possible. Use pre-commit hooks to catch secrets, insecure patterns, and unsafe configurations before code hits the repo. Apply Semgrep rulesets tailored to your stack—for example, detecting hardcoded credentials in Django or unsafe eval() usage in Node.js. 

Code reviews should prioritize security just as much as formatting; if your team enforces style rules but ignores SSRF or IDOR, you're missing critical issues. Integrate static analysis tools into your CI pipeline to automatically flag high-risk code. As a practical tip, maintain your security rules in version control to stay consistent, visible, and easy to evolve across teams.

7. Automate Threat Intelligence and Response

You won’t catch everything upstream, so your response layer needs to be fast, automated, and resilient under pressure.

• Centralize telemetry using tools like Wazuh, Elastic Security, or OpenSearch. Ingest logs from endpoints, cloud APIs, Kubernetes audit events, and identity providers. 

• Automate response with SOAR pipelines. Tools like Tines or StackStorm can chain detections to workflows: revoking compromised credentials, quarantining EC2 instances, and triggering incident channels in Slack.

• Use severity-aware thresholds: auto-resolve high-confidence detections (e.g., leaked AWS keys verified by GuardDuty) while routing ambiguous signals to review queues.



The Surface Shrinks When Security Scales

Reducing your attack surface is a continuous effort. Every new commit, service, or cloud resource can introduce new risks. With the proper guardrails, teams can move from scrambling to patch issues to actively preventing them. Security and velocity aren’t mutually exclusive. With the right tools, both scale together. 

Implementing ASR at scale means dealing with a sprawl of tools and pipelines. Jit tackles that by orchestrating key controls—like static analysis, IaC scanning, and runtime policy enforcement—into a single, unified workflow. It brings structure to fragmented security processes and helps teams enforce posture consistently across the board. Tools like Jit make that achievable by turning ad hoc checks into automated, policy-driven workflows that run wherever your code does. Explore Jit and start reducing risk where it matters most: before it ships.