Skip to content

Latest commit

 

History

History
148 lines (129 loc) · 10.6 KB

threat-modeling.md

File metadata and controls

148 lines (129 loc) · 10.6 KB

Threat Model Analysis for postalserver/postal

Threat: Postal Web Interface Authentication Bypass

  • Description: An attacker exploits a vulnerability in Postal's web interface authentication (e.g., SQL injection, broken authentication logic, session hijacking). They could bypass login procedures and gain unauthorized access to the Postal web interface.
  • Impact:
    • Full control over Postal server configuration.
    • Access to all emails stored in Postal.
    • Ability to create/delete domains and users.
    • Potential for data breaches, denial of service, and reputational damage.
  • Postal Component Affected: Postal Web Interface (specifically authentication modules)
  • Risk Severity: Critical
  • Mitigation Strategies:
    • Regularly update Postal to the latest version to patch known vulnerabilities.
    • Implement strong input validation and output encoding to prevent injection attacks.
    • Enforce strong password policies for web interface users.
    • Use multi-factor authentication (MFA) for web interface access if available or implementable.
    • Conduct regular security audits and penetration testing of the web interface.

Threat: API Key Compromise

  • Description: An attacker obtains a valid Postal API key through various means (e.g., insecure storage, exposed logs, network interception, social engineering). They then use this key to access the Postal API and perform actions as an authorized user.
  • Impact:
    • Unauthorized sending of emails (spam, phishing).
    • Access to email logs and metadata.
    • Modification or deletion of email sending configurations.
    • Potential for reputational damage and service disruption.
  • Postal Component Affected: Postal API, API Key Management
  • Risk Severity: High
  • Mitigation Strategies:
    • Store API keys securely (e.g., using environment variables, secrets management systems, encrypted storage).
    • Rotate API keys regularly.
    • Implement API key access control and restrict permissions based on the principle of least privilege.
    • Monitor API key usage for suspicious activity.
    • Avoid embedding API keys directly in client-side code or public repositories.
    • Use HTTPS for all API communication to prevent interception.

Threat: Email Data Breach via Database Access

  • Description: An attacker gains unauthorized access to the database used by Postal to store emails (e.g., through SQL injection, database misconfiguration, compromised database credentials). They then exfiltrate sensitive email content and attachments.
  • Impact:
    • Exposure of confidential information, personal data, and intellectual property contained in emails.
    • Privacy violations and legal repercussions.
    • Reputational damage and loss of customer trust.
  • Postal Component Affected: Postal Database (and potentially database access layer)
  • Risk Severity: Critical
  • Mitigation Strategies:
    • Securely configure the database server (firewall, access controls).
    • Use strong and unique database credentials.
    • Encrypt database connections and data at rest if possible.
    • Regularly patch and update the database software.
    • Implement database access auditing and monitoring.
    • Apply principle of least privilege for database user access.
    • Ensure proper input validation to prevent SQL injection vulnerabilities in Postal code.

Threat: SMTP Relay Misconfiguration leading to Open Relay

  • Description: Postal is misconfigured to act as an open SMTP relay, allowing anyone to send emails through it without proper authentication or authorization. Attackers exploit this misconfiguration to send spam, phishing emails, or malware, using the Postal server as a launchpad.
  • Impact:
    • Postal server IP address blacklisting, preventing legitimate email delivery.
    • Reputational damage to the domain and organization.
    • Resource exhaustion on the Postal server due to spam traffic.
  • Postal Component Affected: Postal SMTP Server, Relay Configuration
  • Risk Severity: High
  • Mitigation Strategies:
    • Carefully configure SMTP relay settings to restrict relaying to authorized users or networks only.
    • Implement SMTP authentication (e.g., SMTP AUTH) and enforce it.
    • Monitor SMTP traffic for unusual patterns and potential abuse.
    • Regularly review and audit SMTP relay configurations.
    • Implement rate limiting on SMTP connections and email sending.

Threat: Insecure SMTP/STARTTLS Configuration leading to Man-in-the-Middle Attacks

  • Description: Postal's SMTP server is not properly configured to enforce TLS/STARTTLS encryption for email communication. Attackers perform a man-in-the-middle (MitM) attack to intercept unencrypted email traffic between Postal and other mail servers or clients, capturing email content and credentials.
  • Impact:
    • Exposure of sensitive email content in transit.
    • Compromise of email account credentials if transmitted unencrypted.
    • Loss of confidentiality and potential data breaches.
  • Postal Component Affected: Postal SMTP Server, TLS/STARTTLS Configuration
  • Risk Severity: High
  • Mitigation Strategies:
    • Enforce TLS/STARTTLS for all SMTP connections (both incoming and outgoing).
    • Use strong TLS cipher suites and disable weak or outdated ones.
    • Ensure valid and properly configured TLS certificates are used.
    • Regularly check SMTP server configuration for TLS/STARTTLS enforcement.
    • Educate users to only connect to Postal using secure SMTP protocols (STARTTLS).

Threat: Software Vulnerabilities in Postal Code leading to Remote Code Execution (RCE)

  • Description: Postal code contains vulnerabilities (e.g., code injection, deserialization flaws, buffer overflows) that can be exploited by an attacker to execute arbitrary code on the Postal server. This could be achieved through crafted emails, web interface interactions, or API requests.
  • Impact:
    • Full compromise of the Postal server and underlying system.
    • Data breaches, data manipulation, and denial of service.
    • Potential for lateral movement to other systems on the network.
  • Postal Component Affected: Various Postal Modules (depending on the specific vulnerability)
  • Risk Severity: Critical
  • Mitigation Strategies:
    • Regularly update Postal to the latest version to patch known vulnerabilities.
    • Implement secure coding practices during development.
    • Conduct regular code reviews and security audits.
    • Perform penetration testing and vulnerability scanning.
    • Run Postal with least privilege user accounts.
    • Implement input validation and output encoding throughout the codebase.

Threat: Outdated Postal Version exposing Known Vulnerabilities

  • Description: An organization runs an outdated version of Postal that contains publicly known security vulnerabilities. Attackers exploit these known vulnerabilities to compromise the Postal server.
  • Impact:
    • Depends on the specific vulnerabilities present in the outdated version, but can range from data breaches and denial of service to remote code execution.
  • Postal Component Affected: All Postal Components
  • Risk Severity: High (if known critical vulnerabilities exist)
  • Mitigation Strategies:
    • Establish a regular patching and update schedule for Postal.
    • Monitor security advisories and vulnerability databases for Postal and its dependencies.
    • Implement automated update mechanisms where possible.
    • Perform regular vulnerability scans to identify outdated software.

Threat: Improper Handling of Attachments leading to Malware Distribution

  • Description: Postal's handling of email attachments (e.g., during processing, storage, or web interface viewing) contains vulnerabilities. Attackers exploit these vulnerabilities to deliver malware to users who interact with emails processed by Postal.
  • Impact:
    • Malware infection of user devices or systems.
    • Data breaches, data loss, and system compromise.
    • Reputational damage if Postal is used to distribute malware.
  • Postal Component Affected: Postal Attachment Handling Modules, Web Interface (if attachments are viewed there)
  • Risk Severity: High
  • Mitigation Strategies:
    • Implement robust attachment scanning for malware (using external tools if Postal doesn't provide native functionality).
    • Sanitize or quarantine potentially malicious attachments.
    • Restrict attachment types allowed through Postal.
    • Educate users about the risks of opening attachments from unknown senders.
    • Ensure secure configuration of any attachment processing libraries or components used by Postal.

Threat: Email Spoofing and Phishing originating from Compromised Postal Server

  • Description: An attacker compromises a Postal server (through any of the vulnerabilities listed above). They then use the compromised server to send spoofed or phishing emails, appearing to originate from legitimate domains hosted on Postal.
  • Impact:
    • Reputational damage to domains hosted on Postal.
    • Successful phishing attacks against users, leading to credential theft, malware infection, or financial loss.
    • Loss of trust in email communications from domains hosted on Postal.
  • Postal Component Affected: Postal SMTP Server, potentially Web Interface/API for configuration
  • Risk Severity: High
  • Mitigation Strategies:
    • Secure Postal server according to all other mitigation strategies listed.
    • Implement and properly configure SPF, DKIM, and DMARC records for all domains hosted on Postal to prevent spoofing of outgoing emails by external attackers.
    • Monitor outgoing email traffic for suspicious patterns and potential abuse.
    • Implement rate limiting on email sending to detect and prevent bulk spam/phishing attempts.