What’s Vulnerable › Vulnerabilities

CVE-2023-37899: feathersjs socket handler allows abusing implicit toString

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.2% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2023-07-19 · updated 2026-06-17
• Weakness: CWE-754

Description

Feathersjs is a framework for creating web APIs and real-time applications with TypeScript or JavaScript. Feathers socket handler did not catch invalid string conversion errors like `const message = ${{ toString: '' }}` which would cause the NodeJS process to crash when sending an unexpected Socket.io message like `socket.emit('find', { toString: '' })`. A fix has been released in versions 5.0.8 and 4.5.18. Users are advised to upgrade. There is no known workaround for this vulnerability.

Affected products

• feathersjs feathers: before 4.5.18; from 5.0.0 before 5.0.8 — fixed in 4.5.18, 5.0.8

How to fix

Upgrade to a fixed version: feathersjs feathers 4.5.18, 5.0.8. Check the vendor advisory for mitigations.

References

• https://github.com/feathersjs/feathers/blob/crow/CHANGELOG.md#4518-2023-07-19
• https://github.com/feathersjs/feathers/blob/dove/CHANGELOG.md#508-2023-07-19
• https://github.com/feathersjs/feathers/pull/3241
• https://github.com/feathersjs/feathers/pull/3242
• https://github.com/feathersjs/feathers/security/advisories/GHSA-hhr9-rh25-hvf9
• https://github.com/feathersjs/feathers/blob/crow/CHANGELOG.md#4518-2023-07-19
• https://github.com/feathersjs/feathers/blob/dove/CHANGELOG.md#508-2023-07-19
• https://github.com/feathersjs/feathers/pull/3241
• https://github.com/feathersjs/feathers/pull/3242
• https://github.com/feathersjs/feathers/security/advisories/GHSA-hhr9-rh25-hvf9

Get alerted when CVE-2023-37899 or the next vulnerability affects your stack