threat-modeling.md

Threat Model Analysis for getgrav/grav

Threat: Arbitrary File Read

• Description: An attacker exploits a vulnerability in Grav core or a plugin to read sensitive files on the server. This could be achieved by manipulating URL parameters, exploiting file inclusion vulnerabilities, or bypassing access controls. The attacker might target configuration files, content files, or system files to gather information.
• Impact: Information disclosure, including sensitive configuration details, credentials, and content. This information can be used for further attacks, such as privilege escalation or data breaches.
• Affected Grav Component: Core, Plugins, Routing, File Handling Functions
• Risk Severity: High
• Mitigation Strategies:
  • Keep Grav core and plugins updated to patch known vulnerabilities.
  • Implement strict file permission configurations to limit access to sensitive files.
  • Use security plugins that monitor file access and detect suspicious activity.
  • Carefully review plugin and theme code for file handling vulnerabilities before installation.
  • Implement input validation and sanitization to prevent path traversal attacks.

Threat: Arbitrary File Write/Upload

• Description: An attacker exploits a vulnerability in Grav's file upload mechanisms or a plugin to upload or write malicious files to the server. This could involve bypassing file type validation, exploiting insecure file upload endpoints, or leveraging vulnerabilities in plugins that handle file uploads. The attacker might upload web shells, malware, or replace legitimate files with malicious versions.
• Impact: Remote Code Execution (RCE), website defacement, data manipulation, denial of service. Successful file write can lead to complete server compromise.
• Affected Grav Component: Core, Plugins, File Upload Functionality, Media Manager
• Risk Severity: Critical
• Mitigation Strategies:
  • Strictly control file upload functionality and disable it if not necessary.
  • Implement robust file type validation and sanitization on both client and server sides.
  • Configure secure file permissions to prevent unauthorized file writing.
  • Use a Web Application Firewall (WAF) to filter malicious uploads.
  • Regularly audit file upload related code in plugins and themes.
  • Implement Content Security Policy (CSP) to restrict execution of uploaded scripts.

Threat: Vulnerable Plugins

• Description: An attacker exploits known vulnerabilities in installed Grav plugins. Plugins, being third-party code, may contain various security flaws such as XSS, SQL Injection (if plugin interacts with databases), RCE, or insecure file handling. Attackers can leverage public vulnerability databases or exploit zero-day vulnerabilities in popular or less maintained plugins.
• Impact: Wide range of impacts depending on the plugin vulnerability, including XSS, RCE, data breaches, website defacement, denial of service.
• Affected Grav Component: Plugins
• Risk Severity: High to Critical (depending on the vulnerability and plugin's privileges)
• Mitigation Strategies:
  • Carefully vet plugins before installation, prioritizing plugins from trusted and reputable sources.
  • Only install necessary plugins and remove unused ones.
  • Regularly update all installed plugins to the latest versions.
  • Monitor plugin security advisories and vulnerability databases.
  • Consider code audits for critical or high-risk plugins.
  • Implement security plugins that can detect and mitigate common plugin vulnerabilities.

Threat: Brute-Force Attacks on Admin Login

• Description: An attacker attempts to guess administrator credentials by repeatedly trying different username and password combinations on the Grav admin login page. Automated tools are often used to perform these attacks.
• Impact: Unauthorized access to the admin panel, leading to full website compromise, data manipulation, and RCE.
• Affected Grav Component: Admin Panel, User Authentication System
• Risk Severity: High
• Mitigation Strategies:
  • Use strong and unique admin passwords.
  • Implement rate limiting and account lockout mechanisms on the admin login page.
  • Enable Two-Factor Authentication (2FA) for admin accounts.
  • Consider IP address whitelisting for admin access to restrict login attempts to specific networks.
  • Use CAPTCHA or similar mechanisms to prevent automated brute-force attacks.
  • Monitor login attempts and alert on suspicious activity.

Threat: Default Admin Credentials

• Description: An attacker attempts to log in to the Grav admin panel using default or commonly known weak credentials. This is often the first step in automated attacks targeting vulnerable systems.
• Impact: Unauthorized access to the admin panel, leading to full website compromise.
• Affected Grav Component: Admin Panel, User Authentication System, Installation Process
• Risk Severity: Critical (if default credentials are not changed)
• Mitigation Strategies:
  • Force strong password creation during initial Grav setup and prevent the use of default or weak passwords.
  • Regularly audit admin accounts and passwords to ensure they are strong and unique.
  • Educate users on password security best practices.

Threat: Server-Side Template Injection (Twig)

• Description: An attacker injects malicious code into Twig templates through user-controlled input that is not properly sanitized. If Grav application or plugins directly embed user input into Twig templates without escaping, attackers can execute arbitrary code on the server.
• Impact: Remote Code Execution (RCE), information disclosure, website defacement, denial of service.
• Affected Grav Component: Twig Templating Engine, Themes, Plugins
• Risk Severity: Critical
• Mitigation Strategies:
  • Avoid directly embedding user input into Twig templates whenever possible.
  • Use Twig's built-in escaping and sanitization functions to properly handle user input in templates.
  • Carefully review theme and plugin code for potential SSTI vulnerabilities, especially when handling user-provided data in templates.
  • Implement input validation and sanitization before passing data to Twig templates.

Threat: Cross-Site Scripting (XSS) via Markdown

• Description: An attacker injects malicious JavaScript code into Markdown content. If the Markdown parser used by Grav or the rendering process is vulnerable, or if output is not properly sanitized, this malicious script can be executed in users' browsers when they view the content.
• Impact: Cross-Site Scripting (XSS), user session hijacking, website defacement, redirection to malicious sites, information theft.
• Affected Grav Component: Markdown Parser, Content Rendering, Core, Plugins
• Risk Severity: High (in worst case scenarios)
• Mitigation Strategies:
  • Ensure the Markdown parser used by Grav is up-to-date and patched against known vulnerabilities.
  • Sanitize Markdown output before rendering it in the browser, using appropriate escaping and sanitization techniques.
  • Implement Content Security Policy (CSP) to mitigate XSS risks by restricting the sources from which scripts can be loaded.
  • Educate content creators about XSS risks and best practices for writing secure Markdown content.

Threat: Insecure Update Process

• Description: An attacker intercepts or manipulates the Grav update process if it is not properly secured. This could involve man-in-the-middle attacks if updates are downloaded over unencrypted connections or if integrity checks are missing. Attackers could inject malicious code into update packages.
• Impact: Compromise of the Grav installation, Remote Code Execution (RCE), data breaches, website defacement.
• Affected Grav Component: Update Mechanism, Core, Package Management
• Risk Severity: High to Critical
• Mitigation Strategies:
  • Ensure Grav updates are always performed over HTTPS to protect against man-in-the-middle attacks.
  • Verify the integrity of update packages using checksums or digital signatures if provided by Grav.
  • Monitor network traffic during updates for any anomalies.
  • Keep the underlying server and software updated to maintain a secure environment for updates.