AIIR verification and policy gates could report success without enforcing the control (fail-open)

Summary

Several of AIIR's verification and policy paths could return a success/"verified" result without actually enforcing the control they represent — they could fail open rather than fail closed. For a tool whose purpose is trustworthy verification, a consumer relying on these gates may have treated unverified or non-conforming input as verified.

Found during an internal adversarial hardening review of AIIR (not a third-party audit). All paths are fixed in 1.7.0.

Affected paths

• A require_signing policy gate could be satisfied by a forgeable/empty field, so an unsigned or forged-bundle receipt could pass a "signing required" check without a valid signature.
• A CI verification path could report success regardless of the underlying verification result.
• A release-verification gate could advertise policy limits it did not actually enforce.
• A signature-verification path could be silently skipped for certain input categories, exiting success without verifying.

Impact

A consumer relying on these gates (e.g. require_signing, release/policy verification, or the CI check) to block unsigned, forged, or non-conforming receipts could have received a false "verified"/"pass". Exploitation requires reliance on the affected gate; it does not forge valid signatures, nor does it compromise content-addressing or correctly-signed receipts.

Patches

Fixed in 1.7.0. Every affected path now fails closed, each with a regression test. Upgrade to aiir >= 1.7.0.

Workarounds

None for earlier versions other than upgrading. Full cryptographic Sigstore verification (pip install aiir[sign], --verify-signature with --signer-identity/--signer-issuer) provides defense in depth.

Scope note

This advisory covers code present in released versions (< 1.7.0). Separately, an unreleased agent-receipt feature had pre-release forgery findings fixed before it shipped — those were never in a released version and are out of scope.