Horizon Alert
Summary of the vulnerability and why it matters
This vulnerability involves how certain security policies in the `@hulumi/policies` library handle AWS IAM conditions for GitHub OIDC trust. Specifically, an attacker could potentially exploit a weakness in how wildcard conditions are processed, allowing them to bypass established security guardrails by masking subject conditions. The main concern at this stage is confirming the relevance and exposure of this specific policy library within our environment.
- Policies incorrectly validate AWS IAM conditions for GitHub.
- It allows bypassing security guardrails for GitHub OIDC.
- Confirm if this policy library is in use.
Attack Path
How an attacker could exploit the issue
An attacker could exploit this vulnerability by creating a GitHub Actions OIDC trust policy that bypasses security checks. This is possible because the vulnerable component, @hulumi/policies, does not correctly validate certain AWS IAM condition operators, specifically `ForAnyValue:StringLike` when used with wildcard subject conditions. This bypass allows an attacker to potentially gain unauthorized access or execute malicious actions within the cloud environment.
- No authentication required.
- Bypass security checks in OIDC trust policies.
- Unauthorized access to cloud resources.
Live Threat
Current exploitation, exposure, and threat context
When supported by the advisory, attackers could bypass security guardrails by exploiting improper validation of set-qualified AWS IAM condition operators in GitHub OIDC trust policies, potentially hiding wildcard GitHub Actions OIDC subject conditions.
- IAM condition operators.
- Wildcard subject conditions may be hidden.
- Security guardrails could be bypassed.
Operational Fix
Recommended remediation, mitigation, and detection steps
This vulnerability impacts the validation of AWS IAM condition operators in GitHub OIDC trust policies, potentially allowing attackers to bypass security guardrails for GitHub Actions. Ownership likely falls to teams managing CI/CD pipelines, cloud infrastructure, or security tooling that integrates with GitHub Actions and AWS. The immediate priority is to identify all instances of the affected library, confirm their exposure and criticality, and assign an accountable owner for remediation planning.
- Identify affected tooling and owners.
- Verify policy configurations and reachability.
- Plan remediation based on identified risk.
