Skip to content

Latest commit

 

History

History
102 lines (89 loc) · 10.2 KB

attack-surface.md

File metadata and controls

102 lines (89 loc) · 10.2 KB

Attack Surface Analysis for postalserver/postal

Attack Surface: Admin Panel Weak Access Control

  • Description: Unauthorized access to the Postal administrative interface allows attackers to manage the entire mail server, including domains, users, settings, and potentially access sensitive email data.
  • Postal Contribution: Postal provides a web-based admin panel for managing its functionalities. Weak default credentials or insufficient access control mechanisms in this panel directly contribute to this attack surface.
  • Example: Using default credentials like admin/password (if not changed) or exploiting a vulnerability that bypasses authentication to access the admin panel.
  • Impact: Critical. Full compromise of the email infrastructure, data breaches, service disruption, reputation damage, and potential use of the server for malicious activities like spamming or phishing.
  • Risk Severity: Critical
  • Mitigation Strategies:
    • Developers:
      • Enforce Strong Password Policies: Implement strong password requirements for admin users and encourage/force password changes upon initial setup.
      • Multi-Factor Authentication (MFA): Implement and encourage the use of MFA for admin accounts.
      • Regular Security Audits: Conduct regular security audits and penetration testing of the admin panel.
    • Users/Administrators:
      • Change Default Credentials Immediately: Change all default usernames and passwords for the admin panel upon installation.
      • Use Strong, Unique Passwords: Employ strong, unique passwords for all admin accounts and use a password manager.
      • Enable Multi-Factor Authentication (MFA): Enable MFA for all admin accounts if available.
      • Restrict Access: Limit access to the admin panel to only authorized personnel and from trusted networks.

Attack Surface: Web Application Vulnerabilities (XSS, CSRF, Injection)

  • Description: Web application vulnerabilities like Cross-Site Scripting (XSS), Cross-Site Request Forgery (CSRF), and Injection flaws (SQL, Command) in the Postal web interface can be exploited to compromise user accounts, manipulate data, or gain unauthorized access.
  • Postal Contribution: Postal's web interface, built using Ruby on Rails, is susceptible to standard web application vulnerabilities if not developed and maintained with security in mind.
  • Example:
    • SQL Injection: Exploiting a vulnerability in a database query within the web interface to extract sensitive data or modify database records.
    • Command Injection: Exploiting a vulnerability to execute arbitrary system commands on the server via the web interface.
  • Impact: Critical. Potential for full server compromise and control, data breaches, and unauthorized access to sensitive functionalities.
  • Risk Severity: Critical
  • Mitigation Strategies:
    • Developers:
      • Input Validation and Sanitization: Implement robust input validation and sanitization for all user-supplied data in the web interface to prevent injection attacks.
      • Output Encoding: Properly encode output data to prevent XSS vulnerabilities.
      • CSRF Protection: Implement CSRF protection mechanisms (e.g., anti-CSRF tokens) for all state-changing operations.
      • Secure Coding Practices: Follow secure coding practices throughout the development lifecycle, including regular code reviews and security testing.
    • Users/Administrators:
      • Keep Postal Updated: Regularly update Postal to the latest version to benefit from security patches.
      • Use a Web Application Firewall (WAF): Consider deploying a WAF in front of Postal to detect and block common web attacks.

Attack Surface: SMTP Open Relay Misconfiguration

  • Description: Misconfiguring Postal as an open SMTP relay allows anyone to send emails through the server, leading to abuse by spammers, blacklisting of the server's IP, and reputation damage.
  • Postal Contribution: Postal, as a mail server, handles SMTP traffic. Incorrect configuration of relay settings within Postal directly leads to this vulnerability.
  • Example: Attackers using the Postal server to send unsolicited spam emails to a large number of recipients, resulting in the server's IP address being blacklisted by email providers.
  • Impact: High. Server blacklisting, reputation damage, resource consumption due to spam traffic, and potential legal repercussions.
  • Risk Severity: High
  • Mitigation Strategies:
    • Developers:
      • Secure Default Configuration: Ensure Postal's default SMTP relay configuration is secure and not open by default.
      • Clear Documentation: Provide clear and comprehensive documentation on how to properly configure SMTP relay settings and the risks of open relays.
    • Users/Administrators:
      • Restrict SMTP Relay: Configure Postal to only relay emails from authenticated users or trusted networks.
      • Monitor SMTP Traffic: Monitor SMTP traffic for unusual patterns that might indicate abuse.

Attack Surface: API Broken Authentication and Authorization (High Severity Aspects)

  • Description: If Postal exposes an API, vulnerabilities in API authentication and authorization can lead to unauthorized access to sensitive functionalities and data. Focus here is on broken authentication and broken authorization leading to high impact.
  • Postal Contribution: Postal might offer an API for programmatic access. Weaknesses in the API's authentication or authorization mechanisms directly contribute to this attack surface.
  • Example:
    • Broken Authentication: Exploiting a vulnerability to bypass API key authentication and gain full administrative access to the API.
    • Broken Authorization (BOLA/IDOR) leading to data breach: Manipulating API requests to access or modify sensitive data of other users or domains due to insufficient object-level authorization checks.
  • Impact: High. Data breaches, unauthorized data manipulation, and potential service disruption due to unauthorized actions via the API.
  • Risk Severity: High
  • Mitigation Strategies:
    • Developers:
      • Strong API Authentication: Implement robust API authentication mechanisms (e.g., API keys, OAuth 2.0).
      • Proper Authorization (RBAC, ABAC): Implement fine-grained authorization controls to ensure users can only access resources they are authorized to.
      • API Security Audits: Conduct regular security audits and penetration testing of the API.
    • Users/Administrators:
      • Securely Store API Keys: Store API keys securely and avoid embedding them directly in client-side code.
      • Restrict API Access: Limit API access to only authorized applications and users.

Attack Surface: Insecure Default Configurations (High Severity Aspects)

  • Description: Postal might ship with insecure default configurations that, if not changed, can lead to critical vulnerabilities. Focus here is on defaults that lead to high or critical impact.
  • Postal Contribution: Postal's initial setup and default settings directly determine the initial security posture. Insecure defaults with high impact increase the attack surface.
  • Example: Using default database credentials that are easily guessable, leading to unauthorized database access and data breach.
  • Impact: Critical. Database compromise, full data breach, potential for complete system takeover if database access is sufficiently privileged.
  • Risk Severity: Critical
  • Mitigation Strategies:
    • Developers:
      • Secure by Default: Design Postal to be secure by default, minimizing the attack surface out-of-the-box.
      • Security Hardening Guides: Provide clear and comprehensive security hardening guides for administrators.
    • Users/Administrators:
      • Follow Security Hardening Guides: Thoroughly follow official security hardening guides provided by Postal.
      • Review Default Configurations: Carefully review all default configurations and change insecure settings, especially default passwords.

Attack Surface: Lack of TLS/SSL

  • Description: Failure to properly configure TLS/SSL for the web interface, SMTP, and IMAP services exposes communication to eavesdropping and man-in-the-middle attacks, compromising confidentiality and integrity of sensitive data like credentials and email content.
  • Postal Contribution: Postal handles sensitive data transmission over web, SMTP, and IMAP. Lack of proper TLS/SSL configuration in Postal directly creates this vulnerability.
  • Example: An attacker eavesdropping on network traffic to capture usernames, passwords, email content, or other sensitive data transmitted between users and the Postal server over unencrypted connections.
  • Impact: High. Confidentiality breach, data interception, potential credential theft, and man-in-the-middle attacks leading to data manipulation or account compromise.
  • Risk Severity: High
  • Mitigation Strategies:
    • Developers:
      • Enforce TLS/SSL by Default: Configure Postal to enforce TLS/SSL for all web, SMTP, and IMAP services by default.
      • Clear Documentation: Provide clear documentation and guides on how to properly configure TLS/SSL certificates for Postal.
    • Users/Administrators:
      • Enable TLS/SSL for All Services: Ensure TLS/SSL is enabled and properly configured for the web interface, SMTP, and IMAP services.
      • Use Valid Certificates: Use valid and trusted TLS/SSL certificates from a reputable Certificate Authority (CA).