CVE-2025-54070

July 17, 2025, 9:15 p.m.

6.9
Medium

Description

OpenZeppelin Contracts is a library for secure smart contract development. Starting in version 5.2.0 and prior to version 5.4.0, 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. Users should upgrade to version 5.4.0 to receive a patch.

Product(s) Impacted

Vendor Product Versions
Openzeppelin
  • Contracts
  • 5.2.0-5.4.0

Weaknesses

Common security weaknesses mapped to this vulnerability.

CWE-125
Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.

*CPE(s)

Affected systems and software identified for this CVE.

Type Vendor Product Version Update Edition Language Software Edition Target Software Target Hardware Other Information
a openzeppelin contracts 5.2.0-5.4.0 / / / / / / /

CVSS Score

6.9 / 10

CVSS Data - 4.0

  • Attack Vector: NETWORK
  • Attack Complexity: LOW
  • Attack Requirements: NONE
  • Privileges Required: NONE
  • User Interaction: NONE
  • Scope:
  • Confidentiality Impact: NONE
  • Integrity Impact: LOW
  • Availability Impact: LOW
  • Exploit Maturity: NOT_DEFINED
  • 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

    View Vector String

Timeline

Published: July 17, 2025, 7:15 p.m.
Last Modified: July 17, 2025, 9:15 p.m.

Status : Awaiting Analysis

CVE has been recently published to the CVE List and has been received by the NVD.

More info

Source

security-advisories@github.com

*Disclaimer: Some vulnerabilities do not have an associated CPE. To enhance the data, we use AI to infer CPEs based on CVE details. This is an automated process and might not always be accurate.