Описание
Cosign's verify-blob-attestation reports false positive when payload parsing fails
Description
cosign verify-blob-attestation may erroneously report a "Verified OK" result for attestations with malformed payloads or mismatched predicate types. For old-format bundles and detached signatures, this was due to a logic flaw in the error handling of the predicate type validation. For new-format bundles, the predicate type validation was bypassed completely.
Impact
When cosign verify-blob-attestation is used without --check-claims set to true, an attestation that has a valid signature but a malformed or unparsable payload would be incorrectly validated. Additionally, systems relying on --type <predicate type> to reject attestations with mismatched types would be lead to trust the unexpected attestation type.
Patches
v3.0.6, v2.6.3
Workarounds
Always set --check-claims=true for attestation verification.
Пакеты
github.com/sigstore/cosign
>= 3.0.0, < 3.0.6
3.0.6
github.com/sigstore/cosign
< 2.6.3
2.6.3
Связанные уязвимости
Cosign provides code signing and transparency for containers and binaries. Prior to 3.0.6 and 2.6.3, cosign verify-blob-attestation may erroneously report a "Verified OK" result for attestations with malformed payloads or mismatched predicate types. For old-format bundles and detached signatures, this was due to a logic flaw in the error handling of the predicate type validation. For new-format bundles, the predicate type validation was bypassed completely. This vulnerability is fixed in 3.0.6 and 2.6.3.
A flaw was found in Cosign, a tool for code signing and transparency for containers and binaries. A remote attacker could exploit this vulnerability by providing malformed payloads or attestations with mismatched predicate types. This could lead to Cosign erroneously reporting a "Verified OK" result, even when the attestations are invalid. This issue compromises the integrity of the verification process, potentially allowing unverified software to be trusted.
Cosign provides code signing and transparency for containers and binaries. Prior to 3.0.6 and 2.6.3, cosign verify-blob-attestation may erroneously report a "Verified OK" result for attestations with malformed payloads or mismatched predicate types. For old-format bundles and detached signatures, this was due to a logic flaw in the error handling of the predicate type validation. For new-format bundles, the predicate type validation was bypassed completely. This vulnerability is fixed in 3.0.6 and 2.6.3.
Cosign provides code signing and transparency for containers and binar ...