fix(aws): SNS threw IndexError if SubscriptionArn is PendingConfirmation

[kagahd]

Context

The sns_service.py threw the error IndexError[100]: list index out of range upon extracting the region from the field SubscriptionArn of a subscription if the field SubscriptionArn was not an ARN but the value PendingConfirmation.

Description

This PR fixes it by verifying that the SubscriptionArn has at least 4 parts after the split by the character : in order to extract the 4th part, which is the region. If it doesn't, the region is set to unkown. Instead of unknown it could have been set also to regional_client.region or topic.region but I'm not sure if they can differ from the region of a subscription. Feel free to adapt it.

Checklist

• Are there new checks included in this PR? 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

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.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 88.70%. Comparing base (43cae66) to head (5587536).
Report is 11 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #6896      +/-   ##
==========================================
- Coverage   88.73%   88.70%   -0.03%     
==========================================
  Files        1200     1200              
  Lines       34609    34609              
==========================================
- Hits        30710    30701       -9     
- Misses       3899     3908       +9     

Flag	Coverage Δ
prowler	88.70% <ø> (-0.03%)	⬇️

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Components	Coverage Δ
prowler	88.70% <ø> (-0.03%)	⬇️
api	∅ <ø> (∅)

[MrCloudSec]

Good catch @kagahd !!

[prowler-bot]

💚 All backports created successfully

Status	Branch	Result
✅	v4.6
✅	v5.3

Questions ?

Please refer to the Backport tool documentation and see the Github Action logs for details