CVE-2023-34459: @openzeppelin/contracts OpenZeppelin Contracts Using MerkleProof Multiproofs Vulnerability

MODERATE
Advisory Identifier: GHSA-wprv-93r4-jj2p
CVSS 5.3
CWE-354
Published
Advisory Summary

CVE-2023-34459 is a MODERATE (CVSS 5.3) openzeppelin contracts using merkleproof multiproofs vulnerability (CWE-354: Improper Validation of Integrity Check Value) affecting @openzeppelin/contracts libraries in the npm ecosystem. The issue involves openzeppelin contracts using merkleproof multiproofs may allow proving arbitrary leaves for specific trees. Remediation is available by upgrading affected packages to version 4.9.2.

CVE-2023-34459 at a Glance

CVE Identifier CVE-2023-34459
GHSA Identifier GHSA-wprv-93r4-jj2p
Severity MODERATE
CVSS v3.1 Base Score 5.3
CWE Classification CWE-354: Improper Validation of Integrity Check Value
Affected Product @openzeppelin/contracts
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 5.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity High (I:H)
Availability None (A:N)

How to Fix CVE-2023-34459

To remediate this vulnerability, upgrade all affected @openzeppelin/contracts dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

@openzeppelin/contracts fixed: 4.9.2
npm install @openzeppelin/contracts@4.9.2
@openzeppelin/contracts-upgradeable fixed: 4.9.2
npm install @openzeppelin/contracts-upgradeable@4.9.2
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

npm ls @openzeppelin/contracts

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2023-34459, inspect your project dependencies using npm:

npm ls @openzeppelin/contracts

Analyze the terminal output to locate any version of @openzeppelin/contracts in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.9.2), your application is affected.

Note: The npm ls @openzeppelin/contracts command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-354: Improper Validation of Integrity Check Value, where the product does not validate or incorrectly validates the integrity check values or "checksums" of a message. this may prevent it from detecting if the data has been modified or corrupted in transmission. In @openzeppelin/contracts, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Impact 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](https://github.com/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](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.

CVE-2023-34459 Affected @openzeppelin/contracts Versions

2 component(s)
Fixed Versions:
4.9.2
Product / Package Ecosystem Affected Versions Fixed Version
@openzeppelin/contracts
npm
≥ 4.7.0
< 4.9.2
4.9.2
@openzeppelin/contracts-upgradeable
npm
≥ 4.7.0
< 4.9.2
4.9.2

References

Frequently Asked Questions

What is CVE-2023-34459?
CVE-2023-34459 is a security vulnerability in @openzeppelin/contracts involving OpenZeppelin Contracts using MerkleProof multiproofs may allow proving arbitrary leaves for specific trees under CWE-354: Improper Validation of Integrity Check Value.
Which @openzeppelin/contracts versions are affected?
Affected versions include releases prior to 4.9.2 across affected packages: @openzeppelin/contracts, @openzeppelin/contracts-upgradeable.
What version fixes CVE-2023-34459?
Upgrading to 4.9.2 (or the latest patched release for your respective branch) resolves the vulnerability.
Is @openzeppelin/contracts affected?
Yes, @openzeppelin/contracts is affected in releases prior to 4.9.2. Upgrade your dependency to 4.9.2 or later.
Is @openzeppelin/contracts-upgradeable affected?
Yes, @openzeppelin/contracts-upgradeable is affected in releases prior to 4.9.2. Upgrade your dependency to 4.9.2 or later.
What is the CVSS score of CVE-2023-34459?
CVE-2023-34459 has a CVSS v3.1 base score of 5.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N.
What CWE is associated with CVE-2023-34459?
CVE-2023-34459 is classified under CWE-354: Improper Validation of Integrity Check Value (The product does not validate or incorrectly validates the integrity check values or "checksums" of a message. This may prevent it from detecting if the data has been modified or corrupted in transmission.).
How can I check npm dependencies for CVE-2023-34459?
Run the dependency tree command: 'npm ls @openzeppelin/contracts'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-wprv-93r4-jj2p",
  "modified" : "2023-06-19T19:46:37Z",
  "published" : "2023-06-19T19:46:37Z",
  "aliases" : [ "CVE-2023-34459" ],
  "summary" : "OpenZeppelin Contracts using MerkleProof multiproofs may allow proving arbitrary leaves for specific trees",
  "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.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@openzeppelin/contracts"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.7.0"
      }, {
        "fixed" : "4.9.2"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@openzeppelin/contracts-upgradeable"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.7.0"
      }, {
        "fixed" : "4.9.2"
      } ]
    } ]
  } ],
  "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"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-354" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-06-19T19:46:37Z",
    "nvd_published_at" : "2023-06-16T23:15:08Z"
  }
}