Full Report
Microsoft introduces the Cloud Web Applications Threat Matrix, a MITRE ATT&CK-aligned framework that helps defenders understand, prioritize, and mitigate threats to cloud-hosted web apps and serverless platforms. The post Threat matrix: Mapping threats across cloud web applications appeared first on Microsoft Security Blog.
Analysis Summary
# Best Practices: Cloud Web Applications Threat Matrix
## Overview
These practices address the security of cloud-hosted web applications and serverless platforms (such as Azure App Service, AWS Lambda, or Google Cloud Functions). The framework maps specific attack techniques—ranging from initial access to data exfiltration—against the unique architecture of cloud-native web services to help defenders close visibility gaps and prioritize mitigation efforts.
## Key Recommendations
### Immediate Actions
1. **Map Current Assets:** Audit all cloud-hosted web apps and serverless functions to identify which fall under the "Cloud Web Applications" threat model.
2. **Apply Least Privilege to Managed Identities:** Review and strip unnecessary permissions from system-assigned and user-assigned managed identities to prevent lateral movement.
3. **Enable Web Application Firewalls (WAF):** Deploy WAFs to block common exploits like SQL injection, Cross-Site Scripting (XSS), and Local File Inclusion (LFI).
4. **Rotate Secrets:** Identify and rotate any API keys, connection strings, or service principal credentials currently stored in application settings or environment variables.
### Short-term Improvements (1-3 months)
1. **Implement Secrets Management:** Migrate all application secrets from environment variables to secure vaults (e.g., Azure Key Vault, AWS Secrets Manager).
2. **Enable Enhanced Logging:** Configure diagnostic logs for web apps to capture HTTP requests, authentication events, and administrative changes (Control Plane logs).
3. **Harden Source Code Access:** Implement strict Branch Protection rules and MFA for developers to prevent unauthorized code commits that could lead to web shell deployment.
### Long-term Strategy (3+ months)
1. **Integrate Posture Management:** Deploy a Cloud Security Posture Management (CSPM) tool like Microsoft Defender for Cloud to continuously monitor for misconfigurations.
2. **Adopt Zero Trust Architecture:** Move toward "Identity as the Perimeter," ensuring every request to the web application is authenticated and authorized regardless of network location.
3. **Continuous Threat Modeling:** Use the Cloud Web Applications Threat Matrix to run "purple team" exercises, simulating specific techniques like Managed Identity token theft to test detection response.
## Implementation Guidance
### For Small Organizations
- Focus on **automated defaults**. Use built-in cloud provider tools to scan for public-facing vulnerabilities.
- Prioritize **MFA for all developers** and administrative accounts to prevent the "Initial Access" phase of the matrix.
### For Medium Organizations
- Implement **Centralized Logging**. Aggregate logs from all serverless functions into a single workspace to detect patterns of "Discovery" or "Persistence."
- Establish a **vulnerability management cadence** for third-party libraries and dependencies used in web apps.
### For Large Enterprises
- Deploy **Cross-Domain XDR**. Correlate signals between identities (Entra ID), cloud resources (Defender for Cloud), and application activity.
- Automate **Incident Response Playbooks** specifically for cloud-native threats like "Serverless Execution Escape" or "Credential Access via IMDS."
## Configuration Examples
- **Managed Identity Security:** Instead of hardcoding credentials, use:
`DefaultAzureCredential()` in code to pull identities dynamically, ensuring the identity has *only* the specific scope (e.g., "Storage Blob Data Reader") required.
- **Environment Variable Protection:** Shift from `APPSETTING_ConnectionString` to Key Vault references:
`@Microsoft.KeyVault(SecretUri=https://myvault.vault.azure.net/secrets/mysecret/)`
## Compliance Alignment
- **NIST SP 800-53:** Aligns with Access Control (AC) and System and Information Integrity (SI) controls.
- **ISO/IEC 27001:** Supports Annex A controls regarding secure coding and cloud services security.
- **MITRE ATT&CK:** Directly extends the Enterprise Matrix to cover cloud-specific web application sub-techniques.
## Common Pitfalls to Avoid
- **Over-privileged Service Identities:** Granting "Contributor" or "Owner" roles to a web app’s managed identity, allowing an attacker who compromises the app to take over the entire subscription.
- **Ignoring Control Plane Logs:** Monitoring only the application logs (Data Plane) while ignoring the logs that show who modified the app configuration (Control Plane).
- **Hardcoding Secrets in Code/CI-CD:** Leaving credentials in `web.config` or GitHub Actions workflows where they can be harvested during the "Credential Access" phase.
## Resources
- **Threat Matrix for Cloud Web Applications:** `https://aka[.]ms/CloudWebAppsThreatMatrix`
- **MITRE ATT&CK Framework:** `https://attack[.]mitre[.]org/`
- **Threat Matrix for Kubernetes:** `https://aka[.]ms/KubernetesThreatMatrix`
- **Zero Trust Assessment Tool:** `https://microsoft[.]github[.]io/zerotrustassessment/`