CVE-2025-54070: @openzeppelin/contracts OpenZeppelin Contracts Bytes's LastIndexOf Function Vulnerability

MODERATE
Advisory Identifier: GHSA-9rcw-c2f9-2j55
CVSS 0.0
CWE-125
Published
Advisory Summary

CVE-2025-54070 is a MODERATE (CVSS 0.0) openzeppelin contracts bytes's lastindexof function vulnerability (CWE-125: Out-of-bounds Read) affecting @openzeppelin/contracts libraries in the npm ecosystem. The issue involves openzeppelin contracts bytes's lastindexof function with position argument performs out-of-bound memory access on empty buffers. Remediation is available by upgrading affected packages to version 5.4.0.

CVE-2025-54070 at a Glance

CVE Identifier CVE-2025-54070
GHSA Identifier GHSA-9rcw-c2f9-2j55
Severity MODERATE
CVSS v3.1 Base Score 0.0
CWE Classification CWE-125: Out-of-bounds Read
Affected Product @openzeppelin/contracts
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 0.0

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

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

How to Fix CVE-2025-54070

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: 5.4.0
npm install @openzeppelin/contracts@5.4.0
@openzeppelin/contracts-upgradeable fixed: 5.4.0
npm install @openzeppelin/contracts-upgradeable@5.4.0
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-2025-54070, 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 5.4.0), 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-125: Out-of-bounds Read, where the product reads data past the end, or before the beginning, of the intended buffer. 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 The `lastIndexOf(bytes,byte,uint256)` function of the `Bytes.sol` library may access uninitialized memory when the following two conditions hold: 1) the provided buffer length is empty (i.e. `buffer.length == 0`) and position is not `2**256 - 1` (i.e. `pos != type(uint256).max`). The `pos` argument could be used to access arbitrary data outside of the buffer bounds. This could lead to the operation running out of gas, or returning an invalid index (outside of the empty buffer). Processing this invalid result for accessing the `buffer` would cause a revert under normal conditions. When triggered, the function reads memory at offset `buffer + 0x20 + pos`. If memory at that location (outside the `buffer`) matches the search pattern, the function would return an out of bound index instead of the expected `type(uint256).max`. This creates unexpected behavior where callers receive a valid-looking index pointing outside buffer bounds. Subsequent memory accesses that don't check bounds and use the returned index must carefully review the potential impact depending on their setup. Code relying on this function returning `type(uint256).max` for empty buffers or using the returned index without bounds checking could exhibit undefined behavior. ### Patches Upgrade to 5.4.0

CVE-2025-54070 Affected @openzeppelin/contracts Versions

2 component(s)
Fixed Versions:
5.4.0
Product / Package Ecosystem Affected Versions Fixed Version
@openzeppelin/contracts
npm
≥ 5.2.0
< 5.4.0
5.4.0
@openzeppelin/contracts-upgradeable
npm
≥ 5.2.0
< 5.4.0
5.4.0

References

Frequently Asked Questions

What is CVE-2025-54070?
CVE-2025-54070 is a security vulnerability in @openzeppelin/contracts involving OpenZeppelin Contracts Bytes's lastIndexOf function with position argument performs out-of-bound memory access on empty buffers under CWE-125: Out-of-bounds Read.
Which @openzeppelin/contracts versions are affected?
Affected versions include releases prior to 5.4.0 across affected packages: @openzeppelin/contracts, @openzeppelin/contracts-upgradeable.
What version fixes CVE-2025-54070?
Upgrading to 5.4.0 (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 5.4.0. Upgrade your dependency to 5.4.0 or later.
Is @openzeppelin/contracts-upgradeable affected?
Yes, @openzeppelin/contracts-upgradeable is affected in releases prior to 5.4.0. Upgrade your dependency to 5.4.0 or later.
What is the CVSS score of CVE-2025-54070?
CVE-2025-54070 has a CVSS v3.1 base score of 0.0 (MODERATE) with vector string CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:N.
What CWE is associated with CVE-2025-54070?
CVE-2025-54070 is classified under CWE-125: Out-of-bounds Read (The product reads data past the end, or before the beginning, of the intended buffer.).
How can I check npm dependencies for CVE-2025-54070?
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-9rcw-c2f9-2j55",
  "modified" : "2025-07-17T22:06:46Z",
  "published" : "2025-07-17T21:19:32Z",
  "aliases" : [ "CVE-2025-54070" ],
  "summary" : "OpenZeppelin Contracts Bytes's lastIndexOf function with position argument performs out-of-bound memory access on empty buffers",
  "details" : "### Impact\n\nThe `lastIndexOf(bytes,byte,uint256)` function of the `Bytes.sol` library may access uninitialized memory when the following two conditions hold: 1) the provided buffer length is empty (i.e. `buffer.length == 0`) and position is not `2**256 - 1` (i.e. `pos != type(uint256).max`).\n\nThe `pos` argument could be used to access arbitrary data outside of the buffer bounds. This could lead to the operation running out of gas, or returning an invalid index (outside of the empty buffer). Processing this invalid result for accessing the `buffer` would cause a revert under normal conditions.\n\nWhen triggered, the function reads memory at offset `buffer + 0x20 + pos`. If memory at that location (outside the `buffer`) matches the search pattern, the function would return an out of bound index instead of the expected `type(uint256).max`. This creates unexpected behavior where callers receive a valid-looking index pointing outside buffer bounds.\n\nSubsequent memory accesses that don't check bounds and use the returned index must carefully review the potential impact depending on their setup. Code relying on this function returning `type(uint256).max` for empty buffers or using the returned index without bounds checking could exhibit undefined behavior.\n\n### Patches\n\nUpgrade to 5.4.0",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@openzeppelin/contracts"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "5.2.0"
      }, {
        "fixed" : "5.4.0"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@openzeppelin/contracts-upgradeable"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "5.2.0"
      }, {
        "fixed" : "5.4.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/OpenZeppelin/openzeppelin-contracts/security/advisories/GHSA-9rcw-c2f9-2j55"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-54070"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/OpenZeppelin/openzeppelin-contracts/pull/5797"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/OpenZeppelin/openzeppelin-contracts"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/OpenZeppelin/openzeppelin-contracts/releases/tag/v5.4.0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-125" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-07-17T21:19:32Z",
    "nvd_published_at" : "2025-07-17T19:15:25Z"
  }
}