A security vulnerability has been identified in the GitHub CLI that could leak authentication tokens when cloning repositories containing git submodules hosted outside of GitHub.com and ghe.com.
This vulnerability stems from several gh commands used to clone a repository with submodules from a non-GitHub host including gh repo clone, gh repo fork, gh pr checkout. These GitHub CLI commands invoke git with instructions to retrieve authentication tokens using the <code>credential.helper</code> configuration variable for any host encountered.
Prior to 2.63.0, hosts other than GitHub.com and ghe.com are treated as GitHub Enterprise Server hosts and have tokens sourced from the following environment variables before falling back to host-specific tokens stored within system-specific secured storage:
GITHUB_ENTERPRISE_TOKENGH_ENTERPRISE_TOKENGITHUB_TOKEN when CODESPACES environment variable is setThe result being git sending authentication tokens when cloning submodules.
In 2.63.0, these GitHub CLI commands will limit the hosts for which gh acts as a credential helper to source authentication tokens. Additionally, GITHUB_TOKEN will only be used for GitHub.com and ghe.com.
Successful exploitation could lead to a third-party using leaked authentication tokens to access privileged resources.
gh to 2.63.0{
"nvd_published_at": "2024-11-27T22:15:05Z",
"severity": "MODERATE",
"github_reviewed": true,
"cwe_ids": [
"CWE-200"
],
"github_reviewed_at": "2024-11-27T21:43:05Z"
}