Skip to content

Latest commit

 

History

History
40 lines (33 loc) · 6.83 KB

attack-surface.md

File metadata and controls

40 lines (33 loc) · 6.83 KB

Attack Surface Analysis for square/okhttp

Attack Surface: TLS/SSL Vulnerabilities (MITM Attacks)

  • Description: Exploiting weaknesses in TLS/SSL protocol or its implementation to intercept and potentially modify communication between the client and server.
    • OkHttp Contribution: OkHttp relies on the underlying platform's TLS/SSL implementation and its own configuration. Misconfiguration in OkHttp (e.g., disabling certificate validation, using outdated TLS versions) directly weakens TLS security, making MITM attacks possible.
    • Example: An application disables certificate validation in OkHttp using a custom sslSocketFactory and hostnameVerifier to bypass certificate checks, perhaps for testing purposes. If this configuration is mistakenly deployed to production, an attacker can easily perform a MITM attack by presenting a fraudulent certificate, as OkHttp will not verify its authenticity.
    • Impact: Confidential data theft, data manipulation, session hijacking, complete account compromise, and loss of data integrity.
    • Risk Severity: Critical
    • Mitigation Strategies:
      • Enable Default Certificate Validation: Ensure that you are leveraging OkHttp's default and secure certificate validation mechanisms. Avoid custom sslSocketFactory and hostnameVerifier implementations that weaken security unless absolutely necessary and with extreme caution.
      • Enforce Strong TLS Versions: Configure OkHttp to use only strong and up-to-date TLS versions (e.g., TLS 1.3, TLS 1.2). Explicitly disallow older, deprecated versions like SSLv3 or TLS 1.0 if possible, or ensure the underlying platform does not negotiate them.
      • Implement Certificate Pinning (for highly sensitive connections): For critical connections where trust is paramount, implement certificate pinning to explicitly trust only specific certificates or public keys. This significantly reduces the risk of MITM attacks, even if Certificate Authorities are compromised.
      • Regularly Update Platform TLS Libraries: Keep the underlying operating system and platform's TLS/SSL libraries updated to patch known vulnerabilities that OkHttp might rely upon.

Attack Surface: HTTP Header Injection

  • Description: Injecting malicious HTTP headers into requests to manipulate server behavior, bypass security controls, or potentially conduct further attacks.
    • OkHttp Contribution: If application code improperly constructs HTTP headers using user-controlled input and passes them to OkHttp's Headers.Builder or Request.Builder without proper sanitization, OkHttp will faithfully transmit these crafted headers, making the application vulnerable.
    • Example: An application allows users to customize HTTP headers, perhaps for analytics or tracking purposes. If the application directly uses user-provided strings to set header values in OkHttp without validation, an attacker could inject headers like X-Forwarded-For to bypass IP-based access controls, Set-Cookie for session fixation attempts, or even attempt to inject multiple headers by including newline characters (\n) if the server-side is vulnerable to header splitting.
    • Impact: Bypassing security controls (e.g., IP whitelisting), session hijacking, potential for cross-site scripting (in specific server-side misconfigurations), information disclosure, and request smuggling if combined with other vulnerabilities.
    • Risk Severity: High
    • Mitigation Strategies:
      • Strict Input Validation and Sanitization: Thoroughly validate and sanitize all user-controlled input before using it to construct HTTP headers. Implement strict whitelists for allowed characters and patterns in header values.
      • Avoid User-Controlled Headers When Possible: Minimize or eliminate the ability for users to directly control HTTP headers. If custom headers are necessary, use predefined options or structured data that is safely translated into headers by the application code, rather than directly accepting raw header values from users.
      • Use OkHttp's API Safely and Correctly: Utilize OkHttp's Headers.Builder and Request.Builder API in a secure manner. Ensure that header values are properly encoded and validated before being added to the request. Be aware of potential newline injection vulnerabilities if constructing headers from raw strings.

Attack Surface: Insecure Defaults or Misconfiguration (Lenient TLS Configuration)

  • Description: Using insecure default settings or misconfiguring OkHttp in a way that weakens TLS/SSL security, even if the application intends to use HTTPS.
    • OkHttp Contribution: While OkHttp's default TLS configuration is generally secure, developers can inadvertently or intentionally misconfigure it, leading to weakened security. This includes disabling essential security features or allowing weak cryptographic algorithms.
    • Example: A developer, during development or troubleshooting, might disable hostname verification using a custom HostnameVerifier in OkHttp to quickly bypass certificate errors. If this insecure configuration is not removed and is deployed to a production environment, it completely negates the security benefits of HTTPS, allowing trivial MITM attacks even with valid certificates presented by attackers for different domains.
    • Impact: Significantly increased risk of MITM attacks, complete interception of sensitive data in transit, loss of confidentiality and integrity, and potential for full compromise of communication security.
    • Risk Severity: High
    • Mitigation Strategies:
      • Thoroughly Review OkHttp TLS Configuration: Carefully review all OkHttp configuration settings related to TLS/SSL, including sslSocketFactory, hostnameVerifier, protocols, and connectionSpecs. Ensure they are set to secure values and align with security best practices.
      • Avoid Disabling Essential TLS Security Features in Production: Never disable certificate validation or hostname verification in production environments. These are critical security mechanisms for HTTPS.
      • Use Secure and Modern Cipher Suites: Ensure that OkHttp and the underlying platform are configured to use strong and modern cipher suites. Avoid allowing weak or outdated ciphers that are vulnerable to known attacks.
      • Regular Security Audits and Code Reviews: Conduct regular security audits and code reviews, specifically focusing on OkHttp configuration and usage, to identify and rectify any insecure settings or practices. Employ static analysis tools to detect potential misconfigurations.