security: Enforce IMDSv2 on EC2 launch template (CKV_AWS_79) #31
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Remediation for Checkov security check CKV_AWS_79 and CISA Near-Term Essential Security (NES) requirement for EC2 instance metadata protection. Changes: - Add metadata_options block to aws_launch_template.sensor_launch_template - Set http_tokens = 'required' to enforce IMDSv2 (session-oriented) - Set http_put_response_hop_limit = 1 to limit metadata service access - Keep http_endpoint = 'enabled' to maintain metadata availability Security Benefits: - Prevents SSRF attacks against instance metadata service - Requires PUT request before GET (session tokens) - Aligns with AWS security best practices - Satisfies CISA NES control requirements References: - https://docs.aws.amazon.com/securityhub/latest/userguide/ec2-controls.html#ec2-8 - https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/configuring-instance-metadata-service.html - https://www.cisa.gov/resources-tools/resources/near-term-essential-security-nes Testing: Verified with checkov security scanner before and after change. No functional impact - IMDSv2 is backward compatible with AWS SDKs.
- Remove redundant http_put_response_hop_limit (defaults to 1) - Match existing pattern in modules/bastion/instance.tf - Still passes CKV_AWS_79 security check
jmfiola
approved these changes
Nov 24, 2025
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Summary
Remediation for Checkov security check CKV_AWS_79 and CISA Near-Term Essential Security (NES) requirement for EC2 instance metadata protection.
Changes
metadata_optionsblock toaws_launch_template.sensor_launch_templatehttp_tokens = 'required'to enforce IMDSv2 (session-oriented)http_put_response_hop_limit = 1to limit metadata service accesshttp_endpoint = 'enabled'to maintain metadata availabilitySecurity Benefits
Testing
References
Checkov Results
Full scan results attached: checkov-scan-results.txt