Summary

A security vulnerability has been identified in go-gh that could leak authentication tokens intended for GitHub hosts to non-GitHub hosts when within a codespace.

Details

go-gh sources authentication tokens from different environment variables depending on the host involved:

• GITHUB_TOKEN, GH_TOKEN for GitHub.com and ghe.com
• GITHUB_ENTERPRISE_TOKEN, GH_ENTERPRISE_TOKEN for GitHub Enterprise Server

Prior to 2.11.1, auth.TokenForHost could source a token from the GITHUB_TOKEN environment variable for a host other than GitHub.com or ghe.com when within a codespace.

In 2.11.1, auth.TokenForHost will only source a token from the GITHUB_TOKEN environment variable for GitHub.com or ghe.com hosts.

Impact

Successful exploitation could send authentication token to an unintended host.

Remediation and mitigation

1. Upgrade go-gh to 2.11.1
2. Advise extension users to regenerate authentication tokens:
   • Personal access tokens
   • GitHub CLI OAuth app
3. Advise extension users to review their personal security log and any relevant audit logs for actions associated with their account or enterprise

References

• GHSA-55v3-xh23-96gh
• https://nvd.nist.gov/vuln/detail/CVE-2024-53859
• https://docs.github.com/en/apps/using-github-apps/reviewing-and-revoking-authorization-of-github-apps#reviewing-your-authorized-github-apps
• https://docs.github.com/en/authentication/keeping-your-account-and-data-secure/reviewing-your-security-log
• https://docs.github.com/en/enterprise-cloud@latest/admin/monitoring-activity-in-your-enterprise/reviewing-audit-logs-for-your-enterprise/identifying-audit-log-events-performed-by-an-access-token
• https://docs.github.com/en/enterprise-cloud@latest/authentication/keeping-your-account-and-data-secure/managing-your-personal-access-tokens
• https://github.com/cli/go-gh/blob/71770357e0cb12867d3e3e288854c0aa09d440b7/pkg/auth/auth.go#L73-L77
• https://pkg.go.dev/vuln/GO-2024-3295