Improper input validation for some Intel(R) TDX Workload Attestation software within Ring 3: User Applications may allow a denial of service. Unprivileged software adversary with an authenticated user combined with a high complexity attack may enable denial of service. This result may potentially occur via local access when attack requirements are present without special internal knowledge and requires no user interaction. The potential vulnerability may impact the confidentiality (none), integrity (none) and availability (high) of the vulnerable system, resulting in subsequent system confidentiality (none), integrity (none) and availability (none) impacts.

Improper input validation for some Intel(R) TDX Workload Attestation software within Ring 3: User Applications may allow a denial of service. Unprivileged software adversary with an authenticated user combined with a high complexity attack may enable denial of service. This result may potentially occur via local access when attack requirements are present without special internal knowledge and requires no user interaction. The potential vulnerability may impact the confidentiality (none), integrity (none) and availability (high) of the vulnerable system, resulting in subsequent system confidentiality (none), integrity (none) and availability (none) impacts.

Affected: crates.io: tdx_workload_attestation

`GcpTdxHost::verify_launch_endorsement()`, available with the `host-gcp-tdx` feature, read `uefi_golden.tdx.measurements[0]` without checking that the golden measurement contains a TDX measurement. If a launch endorsement's golden measurement had no TDX measurements, the call panicked with an index out of bounds instead of returning an error.

The panic is reached only after the endorsement's signing certificate and signature have been verified. Triggering it therefore requires a correctly signed endorsement that lacks TDX measurements.

Intel describes the issue as improper input validation and classifies it as denial of service, with a CVSS 4.0 base score of 5.7, in INTEL-SA-01520.

The flaw was corrected in [#87](https://github.com/IntelLabs/tdx-workload-attestation/pull/87), released in 0.2.0. The function now returns `Error::ParseError` when the TDX measurement structure is missing or empty.

Reported by [Borys Tsyrulnikov](https://borystsyrulnikov.dev).