BlackTreeIndependent security intelligencerisc0 · risc0-ethereum
Low technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.
Low technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.
Fix not verifiedRISC Zero is a zero-knowledge verifiable general computing platform, with Ethereum integration. The risc0-ethereum repository contains Solidity verifier contracts, Steel EVM view call library, and supporting code. Prior to versions 2.1.1 and 2.2.0, the `Steel.validateCommitment` Solidity library function will return `true` for a crafted commitment with a digest value of zero. This violates the semantics of `validateCommitment`, as this does not commitment to a block that is in the current chain. Because the digest is zero, it does not correspond to any block and there exist no known openings. As a result, this commitment will never be produced by a correct zkVM guest using Steel and leveraging this bug to compromise the soundness of a program using Steel would require a separate bug or misuse of the Steel library, which is expected to be used to validate the root of state opening proofs. A fix has been released as part of `risc0-ethereum` 2.1.1 and 2.2.0. Users for the `Steel` Solidity library versions 2.1.0 or earlier should ensure they are using `Steel.validateCommitment` in tandem with zkVM proof verification of a Steel program, as shown in the ERC-20 counter example, and documentation. This is the correct usage of Steel, and users following this pattern are not at risk, and do not need to take action. Users not verifying a zkVM proof of a Steel program should update their application to do so, as this is incorrect usage of Steel.
RISC Zero is a zero-knowledge verifiable general computing platform, with Ethereum integration. The risc0-ethereum repository contains Solidity verifier contracts, Steel EVM view call library, and supporting code. Prior to versions 2.1.1 and 2.2.0, the `Steel.validateCommitment` Solidity library function will return `true` for a crafted commitment with a digest value of zero. This violates the semantics of `validateCommitment`, as this does not commitment to a block that is in the current chain. Because the digest is zero, it does not correspond to any block and there exist no known openings. As a result, this commitment will never be produced by a correct zkVM guest using Steel and leveraging this bug to compromise the soundness of a program using Steel would require a separate bug or misuse of the Steel library, which is expected to be used to validate the root of state opening proofs. A fix has been released as part of `risc0-ethereum` 2.1.1 and 2.2.0. Users for the `Steel` Solidity library versions 2.1.0 or earlier should ensure they are using `Steel.validateCommitment` in tandem with zkVM proof verification of a Steel program, as shown in the ERC-20 counter example, and documentation. This is the correct usage of Steel, and users following this pattern are not at risk, and do not need to take action. Users not verifying a zkVM proof of a Steel program should update their application to do so, as this is incorrect usage of Steel.
The product does not properly filter, remove, quote, or otherwise manage the invalid use of special elements in user-controlled input, which could cause adverse effect on its behavior and integrity.
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
RISC Zero is a zero-knowledge verifiable general computing platform, with Ethereum integration. The risc0-ethereum repository contains Solidity verifier contracts, Steel EVM view call library, and supporting code. Prior to versions 2.1.1 and 2.2.0, the `Steel.validateCommitment` Solidity library function will return `true` for a crafted commitment with a digest value of zero. This violates the semantics of `validateCommitment`, as this does not commitment to a block that is in the current chain. Because the digest is zero, it does not correspond to any block and there exist no known openings. As a result, this commitment will never be produced by a correct zkVM guest using Steel and leveraging this bug to compromise the soundness of a program using Steel would require a separate bug or misuse of the Steel library, which is expected to be used to validate the root of state opening proofs. A fix has been released as part of `risc0-ethereum` 2.1.1 and 2.2.0. Users for the `Steel` Solidity library versions 2.1.0 or earlier should ensure they are using `Steel.validateCommitment` in tandem with zkVM proof verification of a Steel program, as shown in the ERC-20 counter example, and documentation. This is the correct usage of Steel, and users following this pattern are not at risk, and do not need to take action. Users not verifying a zkVM proof of a Steel program should update their application to do so, as this is incorrect usage of Steel.
The product does not properly filter, remove, quote, or otherwise manage the invalid use of special elements in user-controlled input, which could cause adverse effect on its behavior and integrity.
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
CISA Vulnrichment records proof-of-concept exploitation in its SSVC data. BlackTree has not independently executed or validated exploit material.
CWE-159: Improper Handling of Invalid Use of Special Elements. The product does not properly filter, remove, quote, or otherwise manage the invalid use of special elements in user-controlled input, which could cause adverse effect on its behavior and integrity.
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:UCommon Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.
Operational remediation based on structured source evidence.
Published 24 Jun 2025 · Last source change 24 Jun 2025, 20:49 UTC · CWE-159 · Improper Handling of Invalid Use of Special Elements
Core structured fields are present and their contributing authorities are shown above.
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.