mitigations.md

Mitigation Strategies Analysis for stackexchange/dnscontrol

Mitigation Strategy: Strict File Permissions and Secrets Management (DNSControl-Related Aspects)

1. Mitigation Strategy: Strict File Permissions and Secrets Management (DNSControl-Related Aspects)

• Description:

  1. Identify Service Account: Create a dedicated, unprivileged user account (e.g., dnscontrol-user) for running the DNSControl process.
  2. Restrict Permissions: Set file permissions on credentials.json and dnsconfig.js to be readable and writable only by the dnscontrol-user (e.g., chmod 600 credentials.json on Linux/macOS).
  3. Secrets Manager Integration:
     • Choose a secrets management solution.
     • Store API keys from credentials.json in the secrets manager.
     • Modify the DNSControl execution environment (e.g., a startup script, systemd unit, or CI/CD pipeline configuration) to retrieve secrets from the secrets manager at runtime and provide them to DNSControl. This might involve:
       • Setting environment variables just before executing dnscontrol.
       • Generating a temporary credentials.json file with extremely restricted permissions, populated with the retrieved secrets, and then deleting it immediately after DNSControl finishes. This is less ideal than environment variables but may be necessary depending on the secrets manager and DNSControl's limitations.
     • The specific commands and configuration will depend on your chosen secrets manager and how you run DNSControl.
  4. Remove Plaintext Secrets: After successful integration, remove plaintext secrets from the original credentials.json.

• Threats Mitigated:

  • Unauthorized Access to DNSControl Configuration: (Severity: Critical) - Prevents attackers from gaining control by stealing credentials directly from the configuration files.
  • Compromised DNS Provider API (Partial): (Severity: High) - Reduces impact if the server is compromised, as keys aren't directly on the filesystem.

• Impact:

  • Unauthorized Access to DNSControl Configuration: Risk reduced from Critical to Low (with a properly configured secrets manager).
  • Compromised DNS Provider API: Reduces the blast radius.

• Currently Implemented:

  • File Permissions: Partially. Permissions are restricted, but not to a dedicated service account.
  • Secrets Manager: Not implemented. Keys are in plaintext in credentials.json.

• Missing Implementation:

  • Dedicated Service Account: Create the dnscontrol-user.
  • Secrets Manager Integration: Choose, implement, and integrate a secrets manager with the DNSControl execution environment.
  • Remove Plaintext Secrets: Remove keys from credentials.json after integration.

Mitigation Strategy: API Key Scoping (within DNSControl's Context)

2. Mitigation Strategy: API Key Scoping (within DNSControl's Context)

• Description:

  1. Review Permissions: Examine the permissions of the API keys currently used in credentials.json (or the secrets manager).
  2. Create Scoped Keys: Within your DNS provider's control panel, create new API keys with the minimum necessary permissions for DNSControl's operations. Limit access to specific domains or record types if possible.
  3. Update DNSControl Configuration: Replace the old, broadly-permissioned API keys in your credentials.json (or, preferably, your secrets manager) with the new, scoped API keys. This is a direct configuration change within the DNSControl setup.
  4. Test: Run dnscontrol preview and dnscontrol push with the new keys to ensure everything works as expected.

• Threats Mitigated:

  • Compromised DNS Provider API: (Severity: High) - Limits the damage an attacker can do with a compromised key.
  • Unauthorized Access to DNSControl Configuration (Indirect): (Severity: Critical) - If configuration is accessed, scoped keys limit the impact.

• Impact:

  • Compromised DNS Provider API: Risk reduced (combined with MFA on the provider side, this significantly lowers risk).
  • Unauthorized Access to DNSControl Configuration: Indirectly reduces impact.

• Currently Implemented:

  • Not implemented. Current keys have broad permissions.

• Missing Implementation:

  • All steps: Review, create scoped keys, update DNSControl configuration, and test.

Mitigation Strategy: DNSSEC Configuration (within dnsconfig.js)

3. Mitigation Strategy: DNSSEC Configuration (within dnsconfig.js)

• Description:

  1. Enable DNSSEC (Provider Side): First, enable DNSSEC signing for your domain within your DNS provider's control panel. This usually involves generating keys.
  2. Configure dnsconfig.js: This is the DNSControl-specific part. Modify your dnsconfig.js file to include the appropriate DNSSEC records. DNSControl provides functions (like D) for managing RRSIG, DNSKEY, and DS records. You'll need to obtain the necessary key information from your DNS provider after enabling DNSSEC. Example (simplified):

     D("example.com", REG_NAME, DnsProvider("PROVIDER"),
         // ... other records ...
         DNSKEY(/* ... key parameters from provider ... */),
         RRSIG(/* ... signature parameters ... */),
         // DS record will likely be managed at your registrar, not within DNSControl
     );

  3. Test: Use dnscontrol preview to verify the changes, then dnscontrol push to apply them. Use external DNSSEC validation tools to confirm correct setup.

• Threats Mitigated:

  • DNS Spoofing/Cache Poisoning: (Severity: High) - Prevents attackers from providing false DNS information.

• Impact:

  • DNS Spoofing/Cache Poisoning: Risk reduced from High to Low.

• Currently Implemented:

  • Not implemented.

• Missing Implementation:

  • Configuration of DNSSEC records within dnsconfig.js.

Mitigation Strategy: Code Review and Mandatory dnscontrol preview

4. Mitigation Strategy: Code Review and Mandatory dnscontrol preview

• Description:

  1. Code Review: Establish a formal code review process for all changes to the dnsconfig.js file. Require another developer's approval before merging.
  2. Mandatory dnscontrol preview: Enforce the use of dnscontrol preview before every dnscontrol push. The output must be reviewed to confirm the changes are as expected. This is a direct workflow requirement when using DNSControl.
  3. Documentation: Document the workflow clearly.
  4. (Optional) Automated Enforcement: Consider adding checks to your CI/CD pipeline to enforce the use of dnscontrol preview (e.g., by rejecting commits without a comment indicating it was run and reviewed).

• Threats Mitigated:

  • Errors in dnsconfig.js (Human Error): (Severity: Medium) - Reduces the risk of introducing errors due to typos, incorrect record types, or accidental deletions.

• Impact:

  • Errors in dnsconfig.js: Risk reduced from Medium to Low.

• Currently Implemented:

  • Code Review: Partially. Informal reviews, but no formal process.
  • dnscontrol preview: Encouraged, but not strictly enforced.

• Missing Implementation:

  • Formal Code Review Process: Establish a formal process.
  • Mandatory dnscontrol preview: Enforce its use before every push.

Mitigation Strategy: Dependency Pinning (DNSControl's Dependencies)

5. Mitigation Strategy: Dependency Pinning (DNSControl's Dependencies)

• Description:

  1. Pin Dependencies: Use a dependency management tool (like go.mod if DNSControl is part of a larger Go project, or whatever is appropriate for your build process) to specify the exact versions of DNSControl and all its transitive dependencies. This prevents automatic updates to potentially compromised versions. This directly impacts how DNSControl is built and deployed.
  2. Regular Review: Periodically review and update the pinned dependencies to the latest secure versions, after careful vetting.

• Threats Mitigated:

  • Supply Chain Attacks: (Severity: Medium) - Reduces the risk of using a compromised version of DNSControl or its dependencies.

• Impact:

  • Supply Chain Attacks: Risk reduced from Medium to Low.

• Currently Implemented:

  • Partially. go.mod is used, but dependencies might not be pinned to the most specific versions.

• Missing Implementation:

  • Stricter Pinning: Pin to the most specific versions.
  • Regular Review: Establish a schedule for reviewing and updating.