GHSA-WPRV-93R4-JJ2P
Vulnerability from github – Published: 2023-06-19 19:46 – Updated: 2023-06-19 19:46Impact
When the verifyMultiProof, verifyMultiProofCalldata, processMultiProof, or processMultiProofCalldata 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 inadvertently 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.
Patches
The problem has been patched in 4.9.2.
Workarounds
If you are 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.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "@openzeppelin/contracts"
},
"ranges": [
{
"events": [
{
"introduced": "4.7.0"
},
{
"fixed": "4.9.2"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "npm",
"name": "@openzeppelin/contracts-upgradeable"
},
"ranges": [
{
"events": [
{
"introduced": "4.7.0"
},
{
"fixed": "4.9.2"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2023-34459"
],
"database_specific": {
"cwe_ids": [
"CWE-354"
],
"github_reviewed": true,
"github_reviewed_at": "2023-06-19T19:46:37Z",
"nvd_published_at": "2023-06-16T23:15:08Z",
"severity": "MODERATE"
},
"details": "### Impact\n\nWhen the `verifyMultiProof`, `verifyMultiProofCalldata`, `processMultiProof`, or `processMultiProofCalldata` functions are in use, it is possible to construct merkle trees that allow forging a valid multiproof for an arbitrary set of leaves.\n\nA 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 inadvertently 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.\n\nA 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](https://github.com/OpenZeppelin/merkle-tree) library are safe.\n\n### Patches\n\nThe problem has been patched in 4.9.2.\n\n### Workarounds\n\nIf you are using multiproofs: When constructing merkle trees hash the leaves and do not insert empty nodes in your trees. Using the [@openzeppelin/merkle-tree](https://www.npmjs.com/package/@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.",
"id": "GHSA-wprv-93r4-jj2p",
"modified": "2023-06-19T19:46:37Z",
"published": "2023-06-19T19:46:37Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/OpenZeppelin/openzeppelin-contracts/security/advisories/GHSA-wprv-93r4-jj2p"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-34459"
},
{
"type": "WEB",
"url": "https://github.com/OpenZeppelin/openzeppelin-contracts/commit/4d2383e17186be3e8ccf5a442e9686ecc7de1c55"
},
{
"type": "PACKAGE",
"url": "https://github.com/OpenZeppelin/openzeppelin-contracts"
},
{
"type": "WEB",
"url": "https://github.com/OpenZeppelin/openzeppelin-contracts/releases/tag/v4.9.2"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N",
"type": "CVSS_V3"
}
],
"summary": "OpenZeppelin Contracts using MerkleProof multiproofs may allow proving arbitrary leaves for specific trees"
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.