Skip to content

Latest commit

 

History

History
54 lines (45 loc) · 5.95 KB

attack-surface.md

File metadata and controls

54 lines (45 loc) · 5.95 KB

Attack Surface Analysis for unetworking/uwebsockets

Attack Surface: Malformed Message Exploitation

  • Description: Attackers send messages with invalid data (e.g., incorrect UTF-8, corrupted binary data) to exploit vulnerabilities in the application's message parsing logic. While the vulnerability is in the application, uWebSockets.js delivers the malicious payload.
  • uWebSockets Contribution: uWebSockets.js handles the WebSocket protocol framing and delivers the raw message data to the application. It does not validate the application-level content of the message. This is a crucial point: uWebSockets.js is the conduit for the attack.
  • Example: An attacker sends a text message with invalid UTF-8 characters, hoping to trigger a buffer overflow in the application's text processing code. Or, sends crafted binary data to exploit a vulnerability in a custom binary protocol parser. uWebSockets.js delivers this data.
  • Impact: Application crashes, arbitrary code execution (in severe cases), data corruption.
  • Risk Severity: Critical (if code execution is possible), High (otherwise)
  • Mitigation Strategies:
    • Strict Input Validation: Always validate the content and encoding of incoming messages after receiving them from uWebSockets.js. Use robust parsing libraries. This is the application's responsibility, but it's triggered by data from uWebSockets.js.
    • UTF-8 Validation: For text messages, explicitly validate that the data is valid UTF-8.
    • Schema Validation (Binary): If using a custom binary protocol, define a schema and validate incoming binary data against that schema.
    • Fuzz Testing: Use fuzzing tools to test the application's message parsing logic with a wide range of invalid and unexpected inputs. This testing should include data as received from uWebSockets.js.
    • Error Handling: Implement robust error handling for parsing failures. Never assume that incoming data is valid.

Attack Surface: Compression Bomb (Zip Bomb)

  • Description: Attackers send highly compressed WebSocket messages that expand to a massive size, consuming excessive memory.
  • uWebSockets Contribution: This attack is specifically enabled by the use of WebSocket compression (permessage-deflate), which is a feature directly handled by uWebSockets.js. The library performs the decompression.
  • Example: An attacker sends a small, highly compressed message that expands to several gigabytes when decompressed by uWebSockets.js.
  • Impact: Server memory exhaustion, application crashes, denial of service.
  • Risk Severity: High
  • Mitigation Strategies:
    • Limit Expansion Ratio: Configure uWebSockets.js to limit the maximum expansion ratio for compressed messages. This is a direct configuration of the library.
    • maxPayloadLength (Again): Even with compression, maxPayloadLength (a uWebSockets.js setting) applies to the uncompressed size, providing a hard limit.
    • Disable Compression (If Possible): If compression is not essential, disable it within uWebSockets.js to eliminate this attack vector entirely.
    • Memory Monitoring: Monitor memory usage and trigger alerts if excessive memory is allocated during decompression (handled by uWebSockets.js).

Attack Surface: Dependency Vulnerabilities (uSockets)

  • Description: Vulnerabilities in the underlying uSockets library can be exploited through uWebSockets.js.
  • uWebSockets Contribution: uWebSockets.js directly and completely depends on uSockets. Any vulnerability in uSockets is inherently a vulnerability in uWebSockets.js. This is a direct, fundamental relationship.
  • Example: A buffer overflow vulnerability is discovered in uSockets's handling of certain network packets. This directly impacts uWebSockets.js.
  • Impact: Varies depending on the uSockets vulnerability, potentially ranging from denial of service to arbitrary code execution.
  • Risk Severity: Critical to High (depending on the specific vulnerability)
  • Mitigation Strategies:
    • Keep Updated: Regularly update uWebSockets.js (which will update uSockets) to the latest version. This is the primary mitigation, as it directly addresses the vulnerable dependency.
    • Monitor Security Advisories: Subscribe to security mailing lists or follow the uWebSockets.js and uSockets projects on GitHub to be notified of security updates.
    • Dependency Auditing: Regularly audit all dependencies, including uSockets, for known vulnerabilities.

Attack Surface: Weak TLS Configuration (if applicable)

  • Description: If TLS is used, weak ciphers or outdated protocols can expose communications to eavesdropping or MITM attacks.
    • uWebSockets Contribution: uWebSockets.js directly handles the TLS handshake and encryption/decryption. The configuration of TLS is a uWebSockets.js configuration.
    • Example: The server, through uWebSockets.js's configuration, is set to use TLS 1.0 or 1.1 with weak ciphers.
    • Impact: Compromise of confidentiality and integrity of WebSocket communications.
    • Risk Severity: High
    • Mitigation Strategies:
      • Strong Ciphers: Configure uWebSockets.js to use only strong, modern ciphers (e.g., AES-256-GCM, ChaCha20-Poly1305). This is a direct configuration setting within uWebSockets.js.
      • TLS 1.3 (Preferred): Use TLS 1.3 whenever possible. Avoid TLS 1.0 and 1.1. TLS 1.2 is acceptable if configured with strong ciphers, all configured within uWebSockets.js.
      • Certificate Validation: Ensure proper certificate validation is implemented and enforced.
      • Regular Review: Regularly review and update the TLS configuration within uWebSockets.js.