mitigations.md

Mitigation Strategies Analysis for apache/httpcomponents-client

Mitigation Strategy: Strict Hostname Verification and Certificate Validation

• Description:

  1. Locate HttpClient Initialization: Find where the CloseableHttpClient instance is created (usually using HttpClients.custom() or HttpClientBuilder).
  2. Set Hostname Verifier: Ensure the setSSLHostnameVerifier() method is called on the HttpClientBuilder. Use new DefaultHostnameVerifier() for standard browser-compatible verification. Avoid NoopHostnameVerifier in production.
  3. Trust Store Configuration (If Custom): If a custom trust store is used (not recommended unless absolutely necessary), ensure it's loaded correctly and contains only trusted root and intermediate CA certificates. Avoid using code that blindly trusts all certificates. This involves configuring the SSLContext and using it to create an SSLConnectionSocketFactory.
  4. Certificate Pinning (Optional, but Recommended): If implementing certificate or public key pinning, you'll likely need a custom SSLSocketFactory or to integrate with a library that provides pinning support (and potentially use an adapter to work with HttpComponents Client). This involves storing the expected certificate hash or public key and validating it during the TLS handshake.

• Threats Mitigated:

  • Man-in-the-Middle (MitM) Attacks: (Severity: Critical)
  • Impersonation Attacks: (Severity: Critical)
  • Data Tampering: (Severity: High)

• Impact:

  • MitM Attacks: Risk reduced from Critical to Low (with pinning) or Medium (without pinning).
  • Impersonation Attacks: Risk reduced from Critical to Low (with pinning) or Medium (without pinning).
  • Data Tampering: Risk reduced from High to Low.

• Currently Implemented:

  • Hostname verification is implemented in src/main/java/com/example/util/HttpClientFactory.java using DefaultHostnameVerifier.
  • Default JVM trust store is used.

• Missing Implementation:

  • Certificate pinning is not currently implemented.
  • A formal process for regularly updating the trust store is not documented (although this is more of an operational concern).

Mitigation Strategy: Careful Handling of Redirects

• Description:

  1. Locate HttpClient Initialization: Find where the CloseableHttpClient is created.
  2. Limit Redirects: Use HttpClientBuilder.setMaxRedirects(int maxRedirects) to set a reasonable limit (e.g., 5 or 10).
  3. Custom Redirect Strategy (Optional, but Recommended): Create a custom class that extends DefaultRedirectStrategy. Override the isRedirected() method.
  4. Validate Redirect URL: Inside isRedirected(), get the location header from the HttpResponse. Check:
     • Protocol: Ensure it's https://.
     • Hostname: Verify it matches the expected domain(s).
     • Path (Optional): Perform additional checks.
     • Return false to prevent the redirect if validation fails.
  5. Disable Redirects (If Possible): If automatic redirects are not required, use HttpClientBuilder.disableRedirectHandling().

• Threats Mitigated:

  • Open Redirect Vulnerabilities: (Severity: Medium)
  • Phishing Attacks: (Severity: High)
  • Malware Distribution: (Severity: High)
  • Infinite Redirect Loops: (Severity: Low)

• Impact:

  • Open Redirect Vulnerabilities: Risk reduced from Medium to Low.
  • Phishing Attacks: Risk reduced from High to Medium.
  • Malware Distribution: Risk reduced from High to Medium.
  • Infinite Redirect Loops: Risk reduced from Low to Negligible.

• Currently Implemented:

  • setMaxRedirects(5) is set in src/main/java/com/example/util/HttpClientFactory.java.

• Missing Implementation:

  • A custom RedirectStrategy with URL validation is not implemented.

Mitigation Strategy: Connection Pooling and Management

• Description:

  1. Use PoolingHttpClientConnectionManager: Ensure the HttpClient is built using a PoolingHttpClientConnectionManager.
  2. Configure Connection Limits:
     • Set setMaxTotal() on the connection manager.
     • Set setDefaultMaxPerRoute().
  3. Set Timeouts: Use RequestConfig.Builder to set:
     • setConnectTimeout()
     • setConnectionRequestTimeout()
     • setSocketTimeout()
  4. Proper Resource Release: Use try-with-resources for CloseableHttpClient and CloseableHttpResponse. Ensure response.close() is always called.
  5. Monitor Pool Statistics (Operational): Use PoolingHttpClientConnectionManager.getStats().

• Threats Mitigated:

  • Resource Exhaustion (DoS): (Severity: Medium)
  • Connection Leaks: (Severity: Medium)
  • Stale Connections: (Severity: Low)
  • Application Hangs: (Severity: Medium)

• Impact:

  • Resource Exhaustion (DoS): Risk reduced from Medium to Low.
  • Connection Leaks: Risk reduced from Medium to Low.
  • Stale Connections: Risk reduced from Low to Negligible.
  • Application Hangs: Risk reduced from Medium to Low.

• Currently Implemented:

  • PoolingHttpClientConnectionManager is used.
  • setMaxTotal(200) and setDefaultMaxPerRoute(20) are set.
  • Timeouts are set.
  • Try-with-resources is used.

• Missing Implementation:

  • Connection pool statistics monitoring (more operational).

Mitigation Strategy: Careful Handling of Cookies

• Description:

  1. Use CookieStore: Use a CookieStore (e.g., BasicCookieStore). Associate it with the HttpClientContext.
  2. Inspect Received Cookies: Examine cookies in the CookieStore after receiving a response.
  3. Validate Cookie Attributes: Check Secure, HttpOnly, Domain, and Path.
  4. Avoid Storing Sensitive Data: Minimize sensitive data in cookies.
  5. Custom CookieSpec (Optional): For fine-grained control, create a custom CookieSpec.

• Threats Mitigated:

  • Session Hijacking: (Severity: High)
  • Cross-Site Scripting (XSS) (via Cookies): (Severity: High)
  • Cookie Manipulation: (Severity: Medium)

• Impact:

  • Session Hijacking: Risk reduced from High to Low.
  • XSS (via Cookies): Risk reduced from High to Negligible.
  • Cookie Manipulation: Risk reduced from Medium to Low.

• Currently Implemented:

  • BasicCookieStore is used.
  • Secure and HttpOnly are verified.

• Missing Implementation:

  • No specific validation of Domain and Path attributes.

Mitigation Strategy: Content Encoding and Decoding

• Description:

  1. Enable Automatic Decoding: Ensure automatic content decoding is enabled (usually the default).
  2. Handle Unsupported Encodings: If you encounter an unsupported encoding, handle the error gracefully. Do not process the response body without proper decoding.

• Threats Mitigated:

  • Unexpected Behavior: (Severity: Low)
  • Potential Vulnerabilities (Rare): (Severity: Low)

• Impact:

  • Unexpected Behavior: Risk reduced from Low to Negligible.
  • Potential Vulnerabilities: Risk remains Low.

• Currently Implemented:

  • Automatic content decoding is enabled by default.

• Missing Implementation:

  • No specific error handling for unsupported encodings.

Mitigation Strategy: Request and Response Interceptors

• Description:

  1. Review Existing Interceptors: Examine the code of custom HttpRequestInterceptor or HttpResponseInterceptor implementations.
  2. Security Checks: Ensure interceptors don't introduce vulnerabilities.
  3. Performance Checks: Ensure interceptors don't introduce performance overhead.
  4. Minimize Use: Only use interceptors when necessary.

• Threats Mitigated:

  • Security Bypass: (Severity: Variable)
  • Data Leakage: (Severity: Medium)
  • Performance Degradation: (Severity: Low)

• Impact:

  • Security Bypass: Risk depends on the vulnerability; mitigation reduces risk to Low.
  • Data Leakage: Risk reduced from Medium to Low.
  • Performance Degradation: Risk reduced from Low to Negligible.

• Currently Implemented:

  • A custom HttpRequestInterceptor is used for authorization. Code reviewed.

• Missing Implementation:

  • No specific performance monitoring of the interceptor.