Skip to content

Latest commit

 

History

History
74 lines (63 loc) · 6.32 KB

attack-surface.md

File metadata and controls

74 lines (63 loc) · 6.32 KB

Attack Surface Analysis for signalapp/signal-server

Attack Surface: Publicly Accessible API Endpoints

  • Description: Signal-Server exposes numerous API endpoints to the internet for client applications to interact with. These endpoints are the primary attack surface for external threats.
  • Signal-Server Contribution: Signal-Server is the API server. All client communication goes through these endpoints, making them inherently critical. The complexity of features like messaging, groups, profiles, and attachments increases the number and complexity of these endpoints.
  • Example: An attacker exploits a vulnerability in the /v1/message endpoint to inject malicious code that is then processed by the server, leading to a denial of service or data corruption.
  • Impact: Full compromise of the server, data breaches, denial of service, unauthorized access to user accounts and messages.
  • Risk Severity: Critical
  • Mitigation Strategies:
    • Developers:
      • Rigorous Input Validation
      • Secure Authentication and Authorization
      • Regular Security Audits and Penetration Testing
      • Rate Limiting and DoS Protection
      • Principle of Least Privilege

Attack Surface: Registration Endpoint Abuse

  • Description: The registration endpoint (/v1/register) allows new users to create accounts. If not properly secured, it can be abused for various attacks.
  • Signal-Server Contribution: Signal-Server manages user registration. Vulnerabilities in this specific endpoint directly impact the security and integrity of the user base.
  • Example: An attacker automates registration requests to create a large number of spam accounts, overloading the server resources or using these accounts for malicious activities (e.g., spam messaging).
  • Impact: Denial of service, resource exhaustion, spam proliferation, potential for phishing or social engineering attacks using fake accounts.
  • Risk Severity: High
  • Mitigation Strategies:
    • Developers:
      • CAPTCHA or Similar Anti-Bot Measures
      • Rate Limiting on Registration Endpoint
      • Email/Phone Verification
      • Account Monitoring and Anomaly Detection

Attack Surface: Attachment Storage and Retrieval Vulnerabilities

  • Description: Signal-Server handles the storage and retrieval of media attachments. Vulnerabilities in this area can lead to malware distribution, unauthorized access, or denial of service.
  • Signal-Server Contribution: Signal-Server is responsible for storing and serving attachments. The way it handles file uploads, storage, and downloads directly determines the security of this attack surface.
  • Example: An attacker uploads a malicious file disguised as a legitimate image. If the server doesn't properly validate file types and content, this malware could be stored and served to other users who download the attachment. Alternatively, path traversal vulnerabilities could allow unauthorized access to stored attachments.
  • Impact: Malware distribution, data breaches (unauthorized access to attachments), denial of service (through large file uploads or storage exhaustion), reputational damage.
  • Risk Severity: High
  • Mitigation Strategies:
    • Developers:
      • Strict File Type Validation
      • Antivirus/Malware Scanning on Upload
      • Secure Storage Location and Access Controls
      • Content Security Policy (CSP) Headers
      • Rate Limiting on Upload/Download

Attack Surface: Database Injection Vulnerabilities

  • Description: If Signal-Server uses a database (which it likely does for persistent data), vulnerabilities like SQL injection can allow attackers to directly interact with the database, bypassing application logic.
  • Signal-Server Contribution: Signal-Server code interacts with the database. If developers don't use parameterized queries or ORMs correctly, or if there are vulnerabilities in data sanitization before database queries, SQL injection becomes possible.
  • Example: An attacker crafts a malicious message or profile update containing SQL injection code. If this input is not properly sanitized and is used in a database query, the attacker could execute arbitrary SQL commands, potentially reading sensitive data, modifying data, or even gaining control of the database server.
  • Impact: Data breaches (access to user messages, profiles, keys, etc.), data manipulation, data deletion, denial of service, potential for complete database server compromise.
  • Risk Severity: Critical
  • Mitigation Strategies:
    • Developers:
      • Parameterized Queries or ORM
      • Input Sanitization (Defense in Depth)
      • Principle of Least Privilege for Database Access
      • Regular Security Code Reviews

Attack Surface: Vulnerable Dependencies

  • Description: Signal-Server, like most applications, relies on third-party libraries and frameworks. Using outdated or vulnerable versions of these dependencies introduces known security vulnerabilities.
  • Signal-Server Contribution: Signal-Server's dependency management and update practices directly determine its exposure to vulnerable dependencies. Neglecting dependency updates or using insecure dependency management practices increases the risk.
  • Example: A widely used library in Signal-Server (e.g., a web framework, a JSON parsing library) has a publicly disclosed vulnerability. If Signal-Server uses a vulnerable version of this library, attackers can exploit this known vulnerability to compromise the server.
  • Impact: Depending on the vulnerability, impacts can range from denial of service to remote code execution, data breaches, and full server compromise.
  • Risk Severity: High to Critical
  • Mitigation Strategies:
    • Developers:
      • Dependency Scanning and Management
      • Regular Dependency Updates
      • Dependency Pinning/Locking
      • Security Monitoring for Dependency Vulnerabilities