attack-surface.md

Attack Surface Analysis for mislav/hub

Attack Surface: GitHub API Token Exposure

• Description: Compromise of GitHub API tokens used by hub to authenticate with GitHub.
• Hub Contribution: hub directly relies on API tokens for authentication and directly stores them locally in configuration files (~/.config/hub, .gitconfig), making these files a primary target if local system security is weak. hub's functionality is impossible without these tokens.
• Example: An attacker gains access to a developer's workstation and reads the ~/.config/hub file, extracting the GitHub API token. They then use this token to access the developer's GitHub account and potentially organization repositories, even without knowing the developer's GitHub password. This is a direct consequence of how hub manages authentication.
• Impact: Unauthorized access to GitHub account and repositories, data breaches, code modification, malicious commits, and potential supply chain attacks if the compromised account has write access to critical repositories.
• Risk Severity: High
• Mitigation Strategies:
  • Secure File Permissions: Ensure strict file permissions on ~/.config/hub and .gitconfig to prevent unauthorized local access to token files.
  • Principle of Least Privilege: Grant API tokens only the necessary scopes required for hub's intended use. Avoid overly broad scopes.
  • Credential Manager: Use a dedicated credential manager to store and manage API tokens more securely than plain text files, instead of relying on hub's default configuration file storage.
  • Regular Token Rotation: Periodically rotate GitHub API tokens to limit the window of opportunity if a token is compromised.
  • Avoid Committing Tokens: Absolutely never commit configuration files containing API tokens to version control.

Attack Surface: Git Hook Exploitation via Cloned Repositories (Indirectly Facilitated by Hub)

• Description: Execution of malicious Git hooks from repositories cloned using hub.
• Hub Contribution: hub directly simplifies and encourages repository cloning with commands like hub clone. While the Git hook vulnerability is inherent to Git itself, hub's ease of use in cloning can indirectly increase the likelihood of users cloning repositories from untrusted sources, thus increasing exposure to this risk.
• Example: A developer uses hub clone to quickly clone a repository from an unfamiliar or potentially malicious source. This repository contains a malicious post-checkout Git hook that, when executed during the clone process or later Git operations triggered by hub interactions, installs malware on the developer's system or steals credentials.
• Impact: Local system compromise, malware infection, credential theft, and potential lateral movement within the network if the compromised system is connected to internal resources.
• Risk Severity: Medium to High (depending on the severity of the malicious hook - can be High if it leads to critical system compromise)
• Mitigation Strategies:
  • Repository Source Awareness: Be extremely cautious when cloning repositories from untrusted or unknown sources, especially when using tools like hub that streamline the process. Verify repository legitimacy before cloning.
  • Git Hook Inspection: Before working with any newly cloned repository, but especially from untrusted sources cloned via hub, inspect the .git/hooks directory for unusual or suspicious scripts.
  • Disable Git Hooks (Temporarily): If unsure about a repository's hooks, temporarily disable Git hooks globally or for the specific repository while inspecting it, especially after using hub clone on a new repository. (e.g., git config --local core.hooksPath /dev/null)
  • Security Scanning of Repositories: Implement repository security scanning tools that can detect potentially malicious content, including Git hooks, before cloning or integrating repositories into workflows, especially if hub is used to quickly onboard new repositories.