threat-modeling.md

Threat Model Analysis for mozilla/addons-server

Threat: Malicious Addon Submission with Forged Identity

• Description: An attacker creates a new developer account using a fake or stolen identity, or compromises an existing developer account. They then submit a malicious addon disguised as a legitimate one. This could involve social engineering, phishing, or exploiting weak password practices.
• Impact: Distribution of malicious addons to users, leading to data breaches, malware infections, or other harmful consequences. Erosion of trust in the addon platform.
• Affected Component:
  • accounts app (specifically user registration, authentication, and profile management).
  • devhub app (addon submission and management interface).
  • API endpoints related to user accounts and addon submissions.
• Risk Severity: Critical
• Mitigation Strategies:
  • Developer: Implement strong multi-factor authentication (MFA) for all developer accounts. Enforce strong password policies. Implement robust identity verification during account creation. Regularly review and audit account activity logs.

Threat: Forged Addon Updates

• Description: An attacker intercepts the communication between addons-server and the client (browser/extension manager) during an addon update. They replace the legitimate update with a malicious one. This could involve a Man-in-the-Middle (MitM) attack.
• Impact: Users unknowingly install malicious updates, compromising their systems. This bypasses the initial review process.
• Affected Component:
  • addons app (specifically the update mechanism and API endpoints).
  • signing module (if signature verification is bypassed or compromised).
  • Network communication between server and client.
• Risk Severity: Critical
• Mitigation Strategies:
  • Developer: Ensure all communication between addons-server and clients uses HTTPS with strong TLS configurations. Enforce strict signature verification on the client-side. Implement certificate pinning (if feasible).

Threat: Modification of Addon Files on the Server

• Description: An attacker gains unauthorized access to the server's file system, either through a vulnerability in addons-server or another application running on the server. They modify the .xpi files of existing addons, injecting malicious code after the addon has been signed.
• Impact: Distribution of tampered addons to users, even if the addons were initially reviewed and approved. This bypasses the signing process.
• Affected Component:
  • File storage mechanism (e.g., local filesystem, object storage).
  • Any component that interacts with stored addon files.
• Risk Severity: Critical
• Mitigation Strategies:
  • Developer: Implement strict file system permissions. Run addons-server with the least privilege necessary. Use a secure storage solution (e.g., object storage with strong access controls). Implement File Integrity Monitoring (FIM). Regularly audit server security.

Threat: Tampering with Addon Metadata

• Description: An attacker gains unauthorized access to the database and modifies addon metadata (e.g., name, description, permissions, version). They could change the displayed name to mimic a popular addon, or modify the permissions to request more access than the addon actually needs.
• Impact: Users are misled about the addon's functionality or permissions, potentially leading them to install malicious or unwanted addons. Could be used to bypass review processes.
• Affected Component:
  • addons app (specifically models and views related to addon metadata).
  • Database interactions (ORM or direct SQL queries).
  • API endpoints that expose or modify addon metadata.
• Risk Severity: High
• Mitigation Strategies:
  • Developer: Implement strict input validation and sanitization for all metadata fields. Use parameterized queries or a secure ORM to prevent SQL injection. Implement database access controls to limit write access. Audit changes to addon metadata.

Threat: Tampering with Review Process

• Description: An attacker compromises a reviewer account (through phishing, password guessing, etc.) or exploits a vulnerability in the review workflow. They approve malicious addons or reject legitimate ones.
• Impact: Malicious addons are approved and distributed to users. Legitimate developers are unfairly blocked. Erosion of trust in the review process.
• Affected Component:
  • reviewers app (specifically the review workflow and tools).
  • accounts app (reviewer account management).
  • API endpoints related to the review process.
• Risk Severity: High
• Mitigation Strategies:
  • Developer: Enforce strong MFA for all reviewer accounts. Implement strict access controls and separation of duties. Audit all review actions. Regularly review and update the review workflow. Provide security training for reviewers.

Threat: Exposure of Sensitive Addon Data

• Description: A misconfiguration or vulnerability in addons-server exposes sensitive data, such as addon source code (if stored), developer API keys, or user data (e.g., email addresses, installed addons). This could be due to a directory listing vulnerability, an unauthenticated API endpoint, or a data leak.
• Impact: Loss of intellectual property (addon source code). Compromise of developer accounts. Privacy violations for users.
• Affected Component:
  • Any component that handles sensitive data.
  • Web server configuration (e.g., nginx).
  • API endpoints.
  • Database.
• Risk Severity: High
• Mitigation Strategies:
  • Developer: Regularly review and audit server configurations. Ensure proper access controls are in place. Use secure coding practices to prevent data leaks. Encrypt sensitive data at rest and in transit. Implement Data Loss Prevention (DLP) measures.

Threat: Leakage of Internal API Keys or Credentials

• Description: addons-server uses internal API keys or credentials to interact with other services (e.g., databases, signing services, email providers). These credentials are accidentally exposed, for example, by being hardcoded in the codebase, committed to a public repository, or exposed through a misconfigured environment variable.
• Impact: An attacker could gain access to other services used by addons-server, potentially leading to a wider compromise.
• Affected Component:
  • Any component that interacts with external services.
  • Configuration files.
  • Environment variables.
• Risk Severity: High
• Mitigation Strategies:
  • Developer: Never hardcode credentials in the codebase. Use a secrets management system (e.g., HashiCorp Vault, AWS Secrets Manager). Regularly rotate API keys and credentials. Use environment variables or configuration files with appropriate permissions.

Threat: Exposure of user data through API vulnerabilities.

• Description: An attacker crafts malicious requests to the addons-server API, exploiting vulnerabilities like insufficient input validation or authorization flaws, to access user data they shouldn't have access to.
• Impact: Unauthorized access to user data, potentially including email addresses, installed addons, usage statistics, or other personal information. Privacy violations and potential for further attacks.
• Affected Component:
  • api app (all API endpoints).
  • accounts app (user data management).
  • addons app (addon data management).
• Risk Severity: High
• Mitigation Strategies:
  • Developer: Implement strict input validation and output encoding for all API endpoints. Enforce strong authorization checks to ensure users can only access their own data. Use parameterized queries to prevent SQL injection. Regularly perform security testing (penetration testing, fuzzing) of the API.

Threat: Exploiting addons-server Vulnerabilities to Gain Server Access

• Description: An attacker exploits a vulnerability in the addons-server codebase (e.g., a remote code execution vulnerability, a path traversal vulnerability) to gain unauthorized access to the underlying server operating system.
• Impact: Complete compromise of the server. The attacker could steal data, install malware, disrupt service, or use the server for other malicious purposes.
• Affected Component: Potentially any component of addons-server.
• Risk Severity: Critical
• Mitigation Strategies:
  • Developer: Regularly update addons-server and all its dependencies to the latest versions. Follow secure coding practices. Conduct regular security audits and penetration testing. Run addons-server with the least privilege necessary. Use a secure operating system and follow security hardening guidelines. Implement intrusion detection/prevention systems (IDS/IPS).

Threat: Privilege escalation within the addons-server application.

• Description: An attacker who has a low-privilege account (e.g., a regular developer) exploits a vulnerability in addons-server to gain higher privileges (e.g., reviewer or administrator). This could involve exploiting a logic flaw, a missing authorization check, or a vulnerability in a third-party library.
• Impact: The attacker gains unauthorized access to sensitive data or functionality, potentially allowing them to approve malicious addons, modify system settings, or compromise other user accounts.
• Affected Component:
  • accounts app (user roles and permissions).
  • reviewers app (reviewer privileges).
  • api app (authorization checks).
  • Any component that handles user authentication and authorization.
• Risk Severity: High
• Mitigation Strategies:
  • Developer: Strictly adhere to the principle of least privilege for all user roles and accounts. Implement robust authorization checks for all actions that require elevated privileges. Regularly conduct security audits and code reviews to identify and address potential privilege escalation vulnerabilities. Use a secure framework and libraries that handle authorization securely.