https://vulnerability.circl.lu/sightings/feed 2026-08-14T16:51:50.305751+00:00 Vulnerability-Lookup info@circl.lu python-feedgen Contains only the most 10 recent sightings. https://vulnerability.circl.lu/sighting/957356e4-f3f9-4d29-9408-5729dadf746c/export 2026-08-14T16:51:50.337244+00:00 Automation user https://cvepremium.circl.lu/user/automation {"uuid": "957356e4-f3f9-4d29-9408-5729dadf746c", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2023-34459", "type": "seen", "source": "https://t.me/cibsecurity/65317", "content": "\u203c CVE-2023-34459 \u203c\n\nOpenZeppelin Contracts is a library for smart contract development. Starting in version 4.7.0 and prior to version 4.9.2, when the `verifyMultiProof`, `verifyMultiProofCalldata`, `procesprocessMultiProof`, or `processMultiProofCalldat` functions are in use, it is possible to construct merkle trees that allow forging a valid multiproof for an arbitrary set of leaves.A contract may be vulnerable if it uses multiproofs for verification and the merkle tree that is processed includes a node with value 0 at depth 1 (just under the root). This could happen inadvertedly for balanced trees with 3 leaves or less, if the leaves are not hashed. This could happen deliberately if a malicious tree builder includes such a node in the tree.A contract is not vulnerable if it uses single-leaf proving (`verify`, `verifyCalldata`, `processProof`, or `processProofCalldata`), or if it uses multiproofs with a known tree that has hashed leaves. Standard merkle trees produced or validated with the @openzeppelin/merkle-tree library are safe.The problem has been patched in version 4.9.2.Some workarounds are available. For those using multiproofs: When constructing merkle trees hash the leaves and do not insert empty nodes in your trees. Using the @openzeppelin/merkle-tree package eliminates this issue. Do not accept user-provided merkle roots without reconstructing at least the first level of the tree. Verify the merkle tree structure by reconstructing it from the leaves.\n\n\ud83d\udcd6 Read\n\nvia \"National Vulnerability Database\".", "creation_timestamp": "2023-06-17T08:33:19.000000Z"} 2023-06-17T08:33:19+00:00