Prototype pollution in web3-utils
Priority HIGH 72CWE-1321Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.
Summary
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.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00718 54th percentileScored 2026-11-07
Fix Fixed web3-utils: 4.2.1web3-utils (npm): 4.2.1
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | web3-utils | before 4.2.1 | 4.2.1 | Patch available | CNA |
| — | web3-utils (npm) | 4.0.1 to before 4.2.1 | 4.2.1 | Patch available | GHSA-2g4c-8fpm-c46v |
- web3-utils Vendor— Affected before 4.2.1 Fixed in 4.2.1 Patch available CNA
- web3-utils (npm) Vendor— Affected 4.0.1 to before 4.2.1 Fixed in 4.2.1 Patch available GHSA-2g4c-8fpm-c46v
CPE names CISA-ADP · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:web3:web3-utils:*:*:*:*:*:*:*:* | — | — | — |
- cpe:2.3:a:web3:web3-utils:*:*:*:*:*:*:*:* Versions — — ·—
Remediation
- Fix · CNA web3-utils Fixed in 4.2.1
- Fix · GHSA-2g4c-8fpm-c46v web3-utils (npm) Fixed in 4.2.1 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2024-21505
- 2026-10-03 Alias added: GHSA-2g4c-8fpm-c46v
References
Sources
- CVE-2024-21505 · CVE Program
- CVE-2024-21505 · NVD
- FIRST EPSS
- GHSA-2g4c-8fpm-c46v · GitHub Advisory Database · CC BY 4.0
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