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Supply Chain Attack - Terraform

Description

Terraform dependencies are not pinned, allowing a malicious actor to override the used components with malicious components without leaving a trace.

Impact

Override dependencies or component with malicious content.

Recommendation

Use mechanisms such as git-commits, or artifacts and hashes to verify the data integrity.

Threat

Anonymous attacker from Internet with write access to the provider releases.

Expected Remediation Time

⌚ 15 minutes.

Score

Default score using CVSS 3.1. It may change depending on the context of the src.

Base

  • Attack vector: N
  • Attack complexity: H
  • Privileges required: N
  • User interaction: R
  • Scope: U
  • Confidentiality: N
  • Integrity: L
  • Availability: N

Temporal

  • Exploit code madurity: U
  • Remediation level: O
  • Report confidence: R

Result

  • Vector string: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N/E:U/RL:O/RC:R
  • Score:
    • Base: 3.1
    • Temporal: 2.6
  • Severity:
    • Base: Low
    • Temporal: Low

Score 4.0

Default score using CVSS 4.0 . It may change depending on the context of the src.

Base 4.0

  • Attack vector: N
  • Attack complexity: H
  • Attack Requirements: N
  • Privileges required: N
  • User interaction: P
  • Confidentiality (VC): N
  • Integrity (VI): L
  • Availability (VA): N
  • Confidentiality (SC): N
  • Integrity (SI): N
  • Availability (SA): N

Threat 4.0

  • Exploit madurity: U

Result 4.0

  • Vector string: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U
  • Score:
    • CVSS-BT: 0.6
  • Severity:
    • CVSS-BT: Low

Compliant code

All terraform dependencies are pinned

required_providers {
aws = {
source = "github.com/hashicorp/example"
version = "3.23.0"
}
}

Non compliant code

There are unpinned terraform dependencies

required_providers {
aws = {
source = "hashicorp/aws"
version = "~> 3.23.0"
}
}

Details

Why

Terraform providers are installed as:

  required_providers {
aws = {
source = "hashicorp/aws"
version = "~> 3.23.0"
}
cloudflare = {
source = "cloudflare/cloudflare"
version = "~> 2.20.0"
}
}

not only they are not pinned, but also a version like 2.20.0 has no guarantees because a malicious actor with access to the provider release process can override tags with malicious content, changing the legit 2.20.0 for malicious 2.20.0 without us noticing

Requirements

Fixes

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