CVE-2025-54070 – @openzeppelin/contracts

Package

Manager: npm
Name: @openzeppelin/contracts
Vulnerable Version: >=5.2.0 <5.4.0

Severity

Level: Medium

CVSS v3.1: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:N

CVSS v4.0: 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

EPSS: 0.0006 pctl0.19093

Details

OpenZeppelin Contracts Bytes's lastIndexOf function with position argument performs out-of-bound memory access on empty buffers ### 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

Metadata

Created: 2025-07-17T21:19:32Z
Modified: 2025-07-17T22:06:46Z
Source: https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/07/GHSA-9rcw-c2f9-2j55/GHSA-9rcw-c2f9-2j55.json
CWE IDs: ["CWE-125"]
Alternative ID: GHSA-9rcw-c2f9-2j55
Finding: F111
Auto approve: 1