A Few Notes on AWS Nitro Enclaves–KMS Integration

[carlospolop]

🤖 Automated Content Update

This PR was automatically generated by the HackTricks News Bot based on a technical blog post.

📝 Source Information

• Blog URL: https://blog.trailofbits.com/2026/08/05/a-few-notes-on-aws-nitro-enclaves-kms-integration
• Blog Title: A Few Notes on AWS Nitro Enclaves–KMS Integration
• Suggested Section: Pentesting Cloud > AWS Pentesting > AWS - Post Exploitation > AWS - KMS Post Exploitation, as a Nitro Enclaves–KMS Integration Attacks subsection; cross-reference AWS - Services > AWS - EC2, EBS, ELB, SSM, VPC & VPN Enum > AWS - Nitro Enum

🎯 Content Summary

Overview

The post analyzes the security boundary between AWS Nitro Enclaves and AWS Key Management Service (KMS). KMS can validate Nitro attestation documents, restrict customer-managed key usage according to enclave Platform Configuration Register (PCR) measurements, and encrypt sensitive responses to a public key generated by the requesting enclave. However, these mechanisms do not automatically protect the application protocol around KMS. Because encrypted keys, ciphertexts, identi...

🔧 Technical Details

Wrapped-key substitution: When multiple data keys or shared secrets are wrapped by the same CMK and stored outside a trusted execution environment, an attacker can replace the expected wrapped value with another valid KMS ciphertext. Successful KMS decryption establishes cryptographic validity under the CMK but not application-level identity. Bind wrapped material to trusted object, tenant, purpose, protocol, and version fields using KMS encryption context.

Ciphertext-and-context pair swapping: Encryption context does not prevent substitution if the attacker controls both the wrapped ciphertext and every context field. The attacker can replace them as a matching pair. At least one security-critical context component must be generated or validated from trusted enclave state, and permissions for Encrypt and GenerateDataKey must prevent attackers from manufacturing arbitrary valid ciphertext/context pairs.

<...

🤖 Agent Actions

Done.

Updated:

• src/pentesting-cloud/aws-security/aws-post-exploitation/aws-kms-post-exploitation/README.md

Added:

• A new “Nitro Enclaves–KMS integration attacks” subsection
• Technical coverage for:
  • missing Recipient / weak PCR enforcement
  • wrapped-key and shared-secret substitution
  • ciphertext+context pair swapping
  • local ciphertext relocation with AEAD AAD
  • CMK/alias/account/Region confusion
  • replay/rollback and metadata confusion
• Inline citations and a numbered ## References section
• An internal cross-reference to aws-nitro-enum.md

Verified:

• Internal Nitro link path exists
• Single references section present

Note:

• mdbook build could not be run because mdbook is not installed in this environment.

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📚 Repository Maintenance

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• MD files fixed: 1

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[carlospolop]

🔗 Additional Context

Original Blog Post: https://blog.trailofbits.com/2026/08/05/a-few-notes-on-aws-nitro-enclaves-kms-integration

Content Categories: Based on the analysis, this content was categorized under "Pentesting Cloud > AWS Pentesting > AWS - Post Exploitation > AWS - KMS Post Exploitation, as a Nitro Enclaves–KMS Integration Attacks subsection; cross-reference AWS - Services > AWS - EC2, EBS, ELB, SSM, VPC & VPN Enum > AWS - Nitro Enum".

Repository Maintenance:

• MD Files Formatting: 590 files processed (1 files fixed)

Review Notes:

• This content was automatically processed and may require human review for accuracy
• Check that the placement within the repository structure is appropriate
• Verify that all technical details are correct and up-to-date
• All .md files have been checked for proper formatting (headers, includes, etc.)

Bot Version: HackTricks News Bot v1.0