feat(gcp): add check to detect VMs with multiple network interfaces

[lydiavilchez]

Context

New security check for GCP Compute Engine to detect VM instances configured with multiple network interfaces. VMs with multiple NICs can act as bridges between networks that should remain isolated, potentially allowing attackers to move laterally between network segments.

Description

This PR adds a new GCP check that verifies whether Compute Engine instances have multiple network interfaces configured. The check evaluates all VM instances and reports:

• PASS: Instance has a single network interface
• FAIL: Instance has multiple network interfaces (2 or more)

Note: Instances created by GKE or used as network virtual appliances may legitimately require multiple network interfaces.

Changes include:

Compute Service (compute_service.py):

• Added network_interfaces field to Instance model to store network interface data

New Check (compute_instance_multiple_network_interfaces/)

Steps to review

1. Review the network_interfaces field added to the Instance model in compute_service.py (if applicable)
2. Review how network interfaces are counted in _get_instances()
3. Review the check logic in compute_instance_multiple_network_interfaces.py
4. Review the metadata.json for accuracy

Checklist

• Are there new checks included in this PR? Yes / No
  • If so, do we need to update permissions for the provider? Please review this carefully.
• Review if the code is being covered by tests.
• Review if code is being documented following this specification https://github.com/google/styleguide/blob/gh-pages/pyguide.md#38-comments-and-docstrings
• Review if backport is needed.
• Review if is needed to change the Readme.md
• Ensure new entries are added to CHANGELOG.md, if applicable.

UI

• All issue/task requirements work as expected on the UI
• Screenshots/Video of the functionality flow (if applicable) - Mobile (X < 640px)
• Screenshots/Video of the functionality flow (if applicable) - Table (640px > X < 1024px)
• Screenshots/Video of the functionality flow (if applicable) - Desktop (X > 1024px)
• Ensure new entries are added to CHANGELOG.md, if applicable.

API

• Verify if API specs need to be regenerated.
• Check if version updates are required (e.g., specs, Poetry, etc.).
• Ensure new entries are added to CHANGELOG.md, if applicable.

License

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[github-actions]

✅ All necessary CHANGELOG.md files have been updated.

[github-actions]

✅ Conflict Markers Resolved

All conflict markers have been successfully resolved in this pull request.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 92.93%. Comparing base (144d59d) to head (f4c75e6).
⚠️ Report is 4 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #9702      +/-   ##
==========================================
+ Coverage   92.70%   92.93%   +0.22%     
==========================================
  Files         129      131       +2     
  Lines        3153     3197      +44     
==========================================
+ Hits         2923     2971      +48     
+ Misses        230      226       -4     

Flag	Coverage Δ
prowler-py3.10-gcp	92.86% <100.00%> (+0.16%)	⬆️
prowler-py3.11-gcp	92.86% <100.00%> (+0.16%)	⬆️
prowler-py3.12-gcp	92.80% <100.00%> (+0.10%)	⬆️
prowler-py3.9-gcp	92.80% <100.00%> (+0.10%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Components	Coverage Δ
prowler	92.93% <100.00%> (+0.22%)	⬆️
api	∅ <ø> (∅)

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[github-actions]

🔒 Container Security Scan

Image: prowler:5d3d319
Last scan: 2025-12-30 17:52:45 UTC

📊 Vulnerability Summary

Severity	Count
🔴 Critical	3
Total	3

3 package(s) affected

⚠️ Action Required

Critical severity vulnerabilities detected. These should be addressed before merging:

• Review the detailed scan results
• Update affected packages to patched versions
• Consider using a different base image if updates are unavailable

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📋 Resources:

• Download full report (see artifacts)
• View in Security tab
• Scanned with Trivy