threat-modeling.md

Threat Model Analysis for go-gitea/gitea

Threat: Bypass of Gitea's Authentication Mechanisms

• Description: An attacker exploits vulnerabilities in Gitea's core authentication logic to bypass login procedures. This could involve flaws in session management, password verification algorithms, or two-factor authentication implementation within Gitea's codebase. Successful bypass grants the attacker full access as another user or administrator.
• Impact: Unauthorized access to user accounts, repositories, and administrative functions. Complete data breaches, unauthorized code modifications, and full system compromise.
• Affected Component: Authentication Module (core authentication logic, session handling, 2FA implementation within Gitea).
• Risk Severity: Critical.
• Mitigation Strategies:
  • Regularly apply Gitea security updates and patches that address authentication vulnerabilities.
  • Implement robust session management with secure session identifiers and appropriate timeouts within Gitea's configuration.
  • Enforce strong password policies and consider integration with password complexity enforcement modules if available in Gitea or through plugins.
  • Mandatory two-factor authentication (2FA) for all users, especially administrators, configured and enforced within Gitea.
  • Conduct regular security audits and penetration testing specifically focusing on Gitea's authentication mechanisms.

Threat: Authorization Bypass within Gitea's Permission Model

• Description: An attacker exploits flaws in Gitea's role-based access control (RBAC) implementation to gain unauthorized access to resources. This could involve vulnerabilities in permission checking functions, logic errors in RBAC enforcement across repositories, organizations, or teams within Gitea's code. Successful bypass allows access or modification of resources beyond the attacker's intended privileges.
• Impact: Data breaches, unauthorized code modifications, privilege escalation, and disruption of repository integrity. Users can gain access to sensitive repositories or administrative functions they should not have access to.
• Affected Component: Authorization Module (core permission checking logic, RBAC implementation within Gitea across all levels).
• Risk Severity: High.
• Mitigation Strategies:
  • Thoroughly review and audit Gitea's permission model configuration and access control settings.
  • Apply the principle of least privilege when assigning user permissions within Gitea.
  • Regularly review and audit user permissions and group memberships within Gitea.
  • Keep Gitea updated to patch any authorization-related vulnerabilities in its core code.
  • Implement automated tests to verify the correct functioning of Gitea's authorization model after updates or configuration changes.

Threat: Vulnerabilities in Gitea's Git Protocol Handling

• Description: An attacker exploits bugs in Gitea's implementation of the Git protocol (over SSH or HTTP(S)). This involves sending specially crafted Git commands or objects that trigger critical vulnerabilities like remote code execution, buffer overflows, or memory corruption within Gitea's Git server components.
• Impact: Remote code execution on the Gitea server, allowing complete system compromise. Repository corruption, denial of service, and potential information disclosure.
• Affected Component: Git Protocol Handling Module (core components parsing and processing Git commands and objects over SSH and HTTP(S) within Gitea).
• Risk Severity: Critical.
• Mitigation Strategies:
  • Immediately apply Gitea security updates and patches that address Git protocol vulnerabilities.
  • Restrict access to Git protocol ports (SSH: 22, HTTP(S): 80/443) to only necessary networks or IP ranges using firewall rules.
  • Consider disabling less secure Git protocol features if not required, based on Gitea's configuration options.
  • Implement intrusion detection and prevention systems (IDS/IPS) to monitor for and block malicious Git protocol traffic targeting Gitea.

Threat: Path Traversal or Arbitrary File Read via Git Operations

• Description: An attacker exploits vulnerabilities in how Gitea handles file paths during Git operations (like checkout, clone, archive) within its codebase. By crafting malicious Git repositories or commands, they can bypass path sanitization and read arbitrary files on the Gitea server's filesystem, potentially accessing sensitive configuration files, user data, or source code.
• Impact: Information disclosure, access to sensitive data (configuration files, user data, etc.), potential for further system compromise by leveraging exposed information.
• Affected Component: Git Operations Module (core file path handling within Git commands like checkout, clone, archive, and potentially Git hooks within Gitea).
• Risk Severity: High.
• Mitigation Strategies:
  • Thoroughly sanitize and validate all file paths used in Git operations within Gitea's code.
  • Implement strict path confinement and chrooting for Git processes executed by Gitea if feasible at the operating system level.
  • Regularly audit Gitea's codebase for path traversal vulnerabilities and apply necessary patches.
  • Minimize the privileges of the Gitea server process to limit the impact of potential path traversal vulnerabilities.

Threat: Vulnerabilities in Gitea's Administration Panel

• Description: An attacker targets vulnerabilities specifically within Gitea's administrative interface. This could include authentication bypasses, authorization flaws, or injection vulnerabilities directly within the admin panel code. Successful exploitation grants the attacker full administrative control over the Gitea instance.
• Impact: Unauthorized administrative access, complete system compromise, data manipulation, full control over the Gitea instance and all hosted repositories.
• Affected Component: Administration Panel Module (core code of the administrative interface within Gitea).
• Risk Severity: Critical.
• Mitigation Strategies:
  • Restrict access to the administration panel to only authorized administrators via network segmentation or IP whitelisting.
  • Implement strong, multi-factor authentication specifically for administrative accounts within Gitea.
  • Regularly apply Gitea security updates and patches that address vulnerabilities in the administration panel.
  • Conduct dedicated security audits and penetration testing focusing specifically on Gitea's administration panel security.

Threat: Server-Side Request Forgery (SSRF) via Git Operations

• Description: An attacker manipulates Git operations within Gitea (e.g., through repository URLs in clone or submodule commands) to cause the Gitea server itself to make requests to internal or external resources. This is due to insufficient validation of URLs or improper handling of external requests initiated by Gitea during Git operations. This can be used to scan internal networks, access internal services, or potentially exfiltrate data from internal systems via the Gitea server.
• Impact: Internal network scanning and reconnaissance, access to internal resources and services that should not be publicly accessible, potential for further exploitation of internal systems, data exfiltration from internal networks.
• Affected Component: Git Operations Module (specifically components handling cloning, submodule updates, and potentially Git hooks if they involve external requests within Gitea).
• Risk Severity: High.
• Mitigation Strategies:
  • Implement strict sanitization and validation of repository URLs and any other external inputs used in Git operations within Gitea's code.
  • Restrict the Gitea server's network access to only necessary external resources using firewall rules and network segmentation.
  • Disable or restrict features that involve server-side requests for Git operations if they are not essential.
  • Monitor Gitea server's outbound network traffic for any suspicious or unexpected activity that might indicate SSRF attempts.

Threat: Denial of Service through Resource Exhaustion via Git Operations

• Description: An attacker crafts or uploads maliciously designed Git repositories or initiates resource-intensive Git operations that overwhelm the Gitea server. This could involve excessively large repositories, deeply nested structures, or Git commands that consume excessive CPU, memory, or disk I/O due to inefficiencies or vulnerabilities in Gitea's resource management during Git operations.
• Impact: Service disruption, unavailability of Gitea for legitimate users, potential server instability or crashes, impacting all users and hosted repositories.
• Affected Component: Git Operations Module, Resource Management (handling of Git processes, resource allocation, and limits within Gitea).
• Risk Severity: High.
• Mitigation Strategies:
  • Implement resource limits for Git operations within Gitea's configuration (CPU, memory, disk I/O quotas per repository or user).
  • Implement rate limiting for Git requests to prevent abuse and excessive load.
  • Monitor server resource usage closely and set up alerts for unusual spikes or resource exhaustion.
  • Consider using a dedicated server or container with sufficient resources specifically for Gitea to isolate resource consumption and prevent impact on other services.

Threat: Insecure File Upload Handling Leading to Remote Code Execution

• Description: An attacker exploits vulnerabilities in Gitea's file upload handling within features like issue attachments, wiki uploads, or avatar uploads. This involves uploading malicious files that, when processed or accessed by the Gitea server, can lead to remote code execution. This could be due to insufficient file type validation, vulnerabilities in file processing libraries used by Gitea, or improper handling of uploaded files.
• Impact: Remote code execution on the Gitea server, allowing complete system compromise. Full control over the Gitea instance and the underlying server.
• Affected Component: File Upload Handling Module (across various web features like issues, wikis, avatars within Gitea), File Processing Libraries.
• Risk Severity: Critical.
• Mitigation Strategies:
  • Implement strict file type validation and sanitization on all file uploads within Gitea, using robust whitelisting and blacklisting mechanisms.
  • Store uploaded files in a secure location outside of the web root and ensure they are not directly accessible or executable by the web server.
  • Utilize antivirus and malware scanning on all uploaded files before storage and processing.
  • Configure the web server to prevent execution of uploaded files in upload directories (e.g., using Options -ExecCGI in Apache or similar configurations in other web servers).
  • Regularly update Gitea and all underlying libraries to patch any file upload or file processing related vulnerabilities.

Threat: Cross-Site Scripting (XSS) in Issue Tracker, Pull Request, or Wiki Features Leading to Account Takeover

• Description: An attacker injects malicious JavaScript code into Gitea's issue tracker, pull request descriptions, wiki pages, or other user-content areas. This is due to insufficient input sanitization and output encoding in Gitea's web interface components. When other users view this content, the malicious script executes in their browsers, potentially allowing the attacker to steal session cookies, credentials, or perform actions on behalf of the victim user, including account takeover, especially targeting administrator accounts.
• Impact: Account takeover, especially of administrator accounts, leading to full control over Gitea. Data breaches, unauthorized modifications, and defacement of project information.
• Affected Component: Web Interface Modules (Issue Tracker, Pull Request, Wiki, Markdown Rendering Engine within Gitea).
• Risk Severity: High.
• Mitigation Strategies:
  • Implement robust input sanitization and output encoding in all web features within Gitea to prevent XSS attacks.
  • Regularly update Gitea to patch any XSS vulnerabilities in its web features and rendering engines.
  • Utilize a Content Security Policy (CSP) to mitigate XSS risks by controlling the sources from which the browser is allowed to load resources.
  • Educate users about the risks of XSS and encourage them to report any suspicious content or behavior within Gitea.
  • Conduct regular security testing, including XSS vulnerability scanning, of Gitea's web interface.