Phala dcap-qvl - the Rust/npm/Python DCAP quote verification library used to verify Intel SGX and TDX attestation

Impact

The library fetches Quoting Enclave identity collateral from the provisioning service but never verifies its signature against the certificate chain, and does not enforce MRSIGNER, ISVPRODID or ISVSVN policy on the QE report. An attacker forges QE Identity data to whitelist a Quoting Enclave that is not Intel's, then signs arbitrary quotes that the verifier accepts as genuine. That is total forgery of SGX and TDX remote attestation: a machine can claim to be running an attested confidential workload while running anything at all. For an operator or a customer relying on attestation to prove that model weights only decrypt inside a genuine TDX trust domain, the proof is worthless. This is the highest-scored item in this set and it is a pure software bug in the verifier, not a CPU flaw.

Who can reach it

Whoever controls the machine claiming to be attested, plus the ability to serve or influence the collateral the verifier fetches. No CPU vulnerability, no physical access, no privileged position on the verifier - the verifier simply accepts a forged identity. Anyone running a confidential-compute service whose verification path uses this library is exposed.

What to do

Pure software update, no firmware and no reboot: upgrade to dcap-qvl 0.3.9 or later (npm @phala/dcap-qvl-node / -web 0.3.4+). Fast and cheap to deploy, which is the good news. The important operator action is inventory: DCAP quote verification is usually buried inside a confidential-computing framework or a TEE-attestation SaaS rather than being a dependency anyone declared deliberately, so audit which library your attestation path actually calls. Any attestation accepted by a vulnerable version before the upgrade should be treated as unverified and re-attested - the fix does not retroactively invalidate quotes you already trusted.

References