CVE-2024-21505
web3-utils Prototype Pollution vulnerability
Versions of the package web3-utils before 4.2.1 are vulnerable to Prototype Pollution via the utility functions format and mergeDeep, due to insecure recursive merge. An attacker can manipulate an object's prototype, potentially leading to the alteration of the behavior of all objects inheriting from the affected prototype by passing specially crafted input to these functions.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Versions of the package web3-utils before 4.2.1 are vulnerable to Prototype Pollution via the utility functions format and mergeDeep, due to insecure recursive merge. An attacker can manipulate an object's prototype, potentially leading to the alteration of the behavior of all objects inheriting from the affected prototype by passing specially crafted input to these functions.
- Record
CVE-2024-21505- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P - Weakness
- CWE-1321, CWE-1321
- Updated
- 2026-11-02
EUVDEUVD-2024-0786
Versions of the package web3-utils before 4.2.1 are vulnerable to Prototype Pollution via the utility functions format and mergeDeep, due to insecure recursive merge. An attacker can manipulate an object's prototype, potentially leading to the alteration of the behavior of all objects inheriting from the affected prototype by passing specially crafted input to these functions.
- Record
EUVD-2024-0786- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-2g4c-8fpm-c46v
web3-utils Prototype Pollution vulnerability
Impact:
The mergeDeep() function in the web3-utils package has been identified for Prototype Pollution vulnerability. An attacker has the ability to modify an object's prototype, which could result in changing the behavior of all objects that inherit from the impacted prototype by providing carefully crafted input to function.
Patches:
It has been fixed in web3-utils version 4.2.1 so all packages and apps depending on web3-utils >=4.0.1 and <=4.2.0 should upgrade to web3-utils 4.2.1.
Workarounds:
None
- Record
GHSA-2g4c-8fpm-c46v- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-1321
- Updated
- 2026-11-02
NVD
Versions of the package web3-utils before 4.2.1 are vulnerable to Prototype Pollution via the utility functions format and mergeDeep, due to insecure recursive merge. An attacker can manipulate an object's prototype, potentially leading to the alteration of the behavior of all objects inheriting from the affected prototype by passing specially crafted input to these functions.
- Record
CVE-2024-21505- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-1321
- Updated
- 2026-11-02
OSV
Versions of the package web3-utils before 4.2.1 are vulnerable to Prototype Pollution via the utility functions format and mergeDeep, due to insecure recursive merge. An attacker can manipulate an object's prototype, potentially leading to the alteration of the behavior of all objects inheriting from the affected prototype by passing specially crafted input to these functions.
- Record
CVE-2024-21505- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P - Weakness
- CWE-1321
- Updated
- 2026-11-02
OSVGHSA-2g4c-8fpm-c46v
web3-utils Prototype Pollution vulnerability
Impact:
The mergeDeep() function in the web3-utils package has been identified for Prototype Pollution vulnerability. An attacker has the ability to modify an object's prototype, which could result in changing the behavior of all objects that inherit from the impacted prototype by providing carefully crafted input to function.
Patches:
It has been fixed in web3-utils version 4.2.1 so all packages and apps depending on web3-utils >=4.0.1 and <=4.2.0 should upgrade to web3-utils 4.2.1.
Workarounds:
None
- Record
GHSA-2g4c-8fpm-c46v- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-1321
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
web3-utilsnpm |
4.0.1 up to 4.2.1 | 4.2.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2024-21505 is a high vulnerability (CVSS 7.5) in Web3 Web3-utils, published March 25, 2024. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.72%, the 54th percentile. Fixed in web3-utils 4.2.1.
References
security.snyk.io/vuln/SNYK-JS-WEB3UTILS-6229337
github.com/web3/web3.js/commit/8ed041c6635d807b3da8960ad49e125e3d1b0e80
nvd.nist.gov/vuln/detail/CVE-2024-21505