Attack Surface: Git Protocol Exploitation (HTTP/HTTPS and SSH)
Description: Vulnerabilities in Gitea's implementation of the Git protocol handling, leading to exploits via crafted Git requests.
Gitea Contribution: Gitea directly implements Git protocol handling for repository access (clone, push, pull, etc.). Flaws in this implementation are direct Gitea vulnerabilities.
Example: A specially crafted git clone request exploits a buffer overflow in Gitea's Git parsing logic, resulting in remote code execution on the Gitea server.
Impact: Remote Code Execution, Denial of Service, Information Disclosure.
Risk Severity: Critical to High
Mitigation Strategies:
- Keep Gitea Updated: Immediately apply security updates and patches for Gitea, especially those related to Git protocol handling.
- Restrict Git Protocol Access: Limit Git protocol access to trusted networks or users if possible. Consider SSH key-based authentication for enhanced security.
- Resource Limits: Configure Gitea's resource limits to mitigate potential Denial of Service attacks exploiting Git protocol weaknesses.
Attack Surface: Repository Access Control Bypass
Description: Circumventing Gitea's built-in permission system to gain unauthorized access to repositories, allowing unauthorized read or write operations.
Gitea Contribution: Gitea is responsible for managing and enforcing repository access controls based on users, organizations, teams, and repository visibility settings. Vulnerabilities or misconfigurations in this system are Gitea-specific.
Example: A flaw in Gitea's permission check logic allows a user to bypass repository access controls and push code to a repository they should only have read access to, or no access at all.
Impact: Data Breach (unauthorized access to source code and sensitive data), Data Tampering (unauthorized modification of code and repository history).
Risk Severity: High to Critical
Mitigation Strategies:
- Principle of Least Privilege: Grant users and teams only the minimum necessary permissions required for their roles.
- Regular Permission Audits: Periodically review and audit repository, user, team, and organization permissions within Gitea to identify and rectify any misconfigurations or unintended access.
- Thorough Testing: After any permission configuration changes, rigorously test repository visibility and access controls to ensure they function as intended and prevent unintended access.
Attack Surface: Stored Cross-Site Scripting (XSS) in Web Interface
Description: Injection of malicious JavaScript code into Gitea's web interface that persists and executes when other users interact with the affected content.
Gitea Contribution: Gitea's web interface renders user-generated content from repositories (file contents, commit messages, issues, pull requests) and uses Markdown. Vulnerabilities in Gitea's content rendering and sanitization can lead to XSS.
Example: An attacker injects malicious JavaScript into an issue comment using Markdown. When another user views this issue, the JavaScript executes in their browser within the context of the Gitea application, potentially leading to session hijacking or other malicious actions.
Impact: Account Takeover, Sensitive Data Theft (session cookies, etc.), Defacement of the Gitea interface, Redirection to external malicious websites.
Risk Severity: High
Mitigation Strategies:
- Input Sanitization and Output Encoding (Gitea Development): Ensure Gitea's codebase rigorously sanitizes user inputs and properly encodes outputs when rendering content in the web interface. This is primarily a responsibility for the Gitea development team to address in the application code.
- Content Security Policy (CSP): Implement a strong Content Security Policy (CSP) to limit the sources from which the browser can load resources, significantly reducing the impact of XSS vulnerabilities even if they exist in the application.
- Regular Security Audits and Penetration Testing: Conduct regular security audits and penetration testing specifically targeting XSS vulnerabilities in Gitea's web interface and content rendering mechanisms.
Attack Surface: Command Injection in Gitea Actions (CI/CD) Workflows
Description: Injection of malicious commands into Gitea Actions workflow definitions that are executed by Gitea runners, leading to arbitrary code execution on the runner environment.
Gitea Contribution: Gitea Actions, a built-in CI/CD feature, allows users to define workflows in YAML. If workflow definitions improperly handle user-controlled input in commands, it creates a command injection vulnerability within Gitea's CI/CD system.
Example: A Gitea Actions workflow uses a user-provided repository name in a shell command without proper sanitization. An attacker can craft a malicious repository name containing shell commands that will be executed on the Gitea runner during workflow execution.
Impact: Remote Code Execution on Gitea Action runners, Access to secrets and sensitive data within the runner environment, Potential lateral movement to other systems accessible from the compromised runner.
Risk Severity: High to Critical
Mitigation Strategies:
- Minimize User-Controlled Input in Commands: Avoid using user-controlled input directly within commands in Gitea Actions workflow definitions as much as possible.
- Strict Input Sanitization and Validation: If user input must be used in commands, implement rigorous sanitization and validation to prevent command injection. Use parameterized commands or safer alternatives to shell execution where feasible.
- Principle of Least Privilege for Runners: Configure Gitea Action runners to operate with the minimum necessary privileges. Isolate runner environments from sensitive systems to limit the potential impact of runner compromise.
- Secure Workflow Definition Review: Implement a mandatory review process for all Gitea Actions workflow definitions to identify and prevent potential command injection vulnerabilities before they are deployed.