title: Ability to bypass attestation verification in sigstore PolicyController
description: PolicyController is a utility used to enforce supply chain policy in Kubernetes clusters. In versions prior to 0.2.1 PolicyController will report a false positive, resulting in an admission when it should not be admitted when there is at least one attestation with a valid signature and there are NO attestations of the type being verified (--type defaults to "custom"). An example image that can be used to test this is `ghcr.io/distroless/static@sha256:dd7614b5a12bc4d617b223c588b4e0c833402b8f4991fb5702ea83afad1986e2`. Users should upgrade to version 0.2.1 to resolve this issue. There are no workarounds for users unable to upgrade.
problem types: CWE-347: Improper Verification of Cryptographic Signature
affected:
{
product: policy-controller
vendor: sigstore
versions:
status: affected, version: < 0.2.1
}
metrics:
cvssV3_1: [
attackComplexity: HIGH
attackVector: NETWORK
availabilityImpact: HIGH
baseScore: 7.1
baseSeverity: HIGH
confidentialityImpact: HIGH
integrityImpact: HIGH
privilegesRequired: LOW
scope: UNCHANGED
userInteraction: REQUIRED
vectorString: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H
version: 3.1
]