mitigations.md

Mitigation Strategies Analysis for labstack/echo

Mitigation Strategy: Strict Middleware Ordering and Auditing (Echo-Specific)

• Mitigation Strategy: Strict Middleware Ordering and Auditing (Echo-Specific)

  • Description:

    1. Define a Standard Order (Echo-Specific): Create documentation that explicitly defines the order in which Echo middleware should be applied using e.Use(). This order must prioritize security-critical middleware that interacts with Echo's Context or request/response handling. Example order (prioritizing Echo-specific concerns):
       • Authentication (using Echo's context for user data)
       • Authorization (using Echo's context and routing information)
       • CORS (using Echo's built-in CORS middleware)
       • Request ID (for tracing within Echo's request lifecycle)
       • Input Validation (specifically validating data bound using Echo's c.Bind(), c.Param(), etc.)
       • Rate Limiting (if using an Echo-specific rate limiting middleware)
    2. Enforce the Order (Echo-Specific): In the main application setup where the Echo instance (e := echo.New()) is created, apply middleware using e.Use() in the exact order specified. Avoid adding middleware within individual route handlers.
    3. Regular Audits (Echo-Specific): Regularly review the e.Use() calls to ensure the defined order is maintained. Check for any middleware that might be bypassing security checks due to incorrect placement. Audit any custom middleware that interacts with the echo.Context.
    4. Document Skipper Logic (Echo-Specific): If any middleware uses the Skipper function (a feature specific to Echo middleware), document the conditions under which the middleware is skipped very clearly. This is crucial because Skipper can bypass middleware execution.

  • Threats Mitigated:

    • Authentication Bypass (Severity: Critical): Incorrect order could allow requests to bypass authentication checks implemented within Echo middleware.
    • Authorization Bypass (Severity: Critical): Similar to above, but for authorization checks within Echo middleware.
    • CORS Misconfiguration (Severity: High): Incorrect placement or configuration of Echo's built-in CORS middleware.
    • Middleware-Specific Vulnerabilities (Severity: Variable): Exploits targeting flaws in custom Echo middleware or how it interacts with echo.Context.
    • Skipper Abuse (Severity: High): Malicious or unintentional misuse of the Skipper function to bypass security middleware.

  • Impact:

    • Authentication/Authorization Bypass: Risk reduced from Critical to Low (assuming the middleware itself is robust).
    • CORS Misconfiguration: Risk reduced from High to Low (assuming correct configuration of Echo's CORS middleware).
    • Middleware-Specific Vulnerabilities: Risk significantly reduced.
    • Skipper Abuse: Risk reduced from High to Low.

  • Currently Implemented: Partially. Middleware order is generally followed, but there's no formal document. Audits are sporadic. Skipper is used in AuthMiddleware, but the logic isn't well-documented.

  • Missing Implementation:

    • Formal documentation of middleware order (specifically for e.Use()).
    • Regular, scheduled audits of e.Use() calls.
    • Comprehensive documentation of Skipper logic in AuthMiddleware.

Mitigation Strategy: Context Immutability and Validation (Echo-Specific)

• Mitigation Strategy: Context Immutability and Validation (Echo-Specific)

  • Description:

    1. Read-Only Context (Preferential, Echo-Specific): Within Echo request handlers, treat the echo.Context as read-only whenever possible. Access data using c.Get(), but avoid c.Set() unless absolutely necessary. This minimizes unintended side effects within Echo's request handling.
    2. Justified Modifications (Echo-Specific): If a handler must modify the echo.Context (e.g., to store data for subsequent Echo middleware), document the reason clearly. Explain why c.Set() is necessary.
    3. Validation of Changes (Echo-Specific): If Echo middleware modifies the echo.Context, add validation logic within that middleware to ensure the changes are safe and don't introduce vulnerabilities within Echo's processing.
    4. Strongly-Typed Keys (Echo-Specific): When using c.Set() and c.Get() with the echo.Context, define constants for the keys (e.g., const UserIDKey = "user_id"). This prevents key collisions that could lead to unexpected behavior within Echo.
    5. Avoid Sensitive Data in Context: Never store sensitive data directly in the echo.Context.

  • Threats Mitigated:

    • Context Manipulation Attacks (Severity: High): Prevents attackers from injecting malicious data into the echo.Context, which could be used to bypass security checks within Echo's middleware chain or influence Echo's behavior.
    • Data Leakage (Severity: Medium): Reduces the risk of accidentally exposing sensitive data stored in the echo.Context.
    • Logic Errors (Severity: Medium): Prevents bugs caused by unintended echo.Context modifications.

  • Impact:

    • Context Manipulation Attacks: Risk reduced from High to Low.
    • Data Leakage: Risk reduced from Medium to Low.
    • Logic Errors: Risk reduced from Medium to Low.

  • Currently Implemented: Partially. Handlers generally avoid modifying the context, but there's no strict enforcement. Strongly-typed keys are not consistently used.

  • Missing Implementation:

    • Formal code review guidelines to enforce read-only echo.Context usage.
    • Validation logic within Echo middleware that modifies the context.
    • Consistent use of strongly-typed keys for c.Set() and c.Get().

Mitigation Strategy: Strict Route Definitions and Parameter Validation (Echo-Specific)

• Mitigation Strategy: Strict Route Definitions and Parameter Validation (Echo-Specific)

  • Description:

    1. Specific Routes (Echo-Specific): Define routes using e.GET(), e.POST(), etc., as precisely as possible. Avoid overly broad wildcards or regular expressions in the route paths.
    2. Parameter Binding and Validation (Echo-Specific): Use Echo's built-in parameter binding features:
       • c.Param("id"): To extract route parameters (e.g., /users/:id).
       • c.QueryParam("sort"): To extract query parameters (e.g., /users?sort=asc).
       • c.FormValue("name"): To extract form data.
       • c.Bind(&user): To bind request data (JSON, XML, form) to a struct.
       • Immediately after using any of these, validate the extracted data. Check type, format, and range. Leverage Echo's validator integration if possible.
    3. Avoid Route Overlap (Echo-Specific): Carefully review the route definitions (all calls to e.GET(), e.POST(), etc.) to ensure there are no overlapping routes.
    4. Regular Expression Review (Echo-Specific, if used): If regular expressions are used in Echo route definitions, review them for ReDoS vulnerabilities.

  • Threats Mitigated:

    • Route Hijacking (Severity: High): Prevents attackers from accessing unintended Echo handlers by manipulating route parameters.
    • Injection Attacks (Severity: High): Parameter validation (using Echo's binding features) prevents injection attacks that might be attempted through route parameters, query parameters, or form data processed by Echo.
    • Regular Expression Denial of Service (ReDoS) (Severity: Medium): Mitigates ReDoS if regular expressions are used in Echo route definitions.

  • Impact:

    • Route Hijacking: Risk reduced from High to Low.
    • Injection Attacks: Risk reduced from High to Low (in conjunction with general input validation).
    • ReDoS: Risk reduced from Medium to Low.

  • Currently Implemented: Partially. Parameter binding is used, but validation is inconsistent. Route overlap checks are not formally performed.

  • Missing Implementation:

    • Consistent and comprehensive parameter validation immediately after using Echo's binding functions.
    • Formal route review process.
    • Review of regular expressions used in Echo routes.

Mitigation Strategy: Secure Error Handling (Echo-Specific)

• Mitigation Strategy: Secure Error Handling (Echo-Specific)

  • Description:

    1. Custom Error Handler (Echo-Specific, Production): Create a custom error handler using e.HTTPErrorHandler. This handler should:
       • Log the full error details (including stack traces, and importantly, the echo.Context).
       • Return a generic error message to the client, without revealing any internal details from the echo.Context or Echo's internal state.

         func customHTTPErrorHandler(err error, c echo.Context) {
             // ... (same code as before, but emphasize logging the c echo.Context) ...
             log.Printf("Echo Context: %+v", c) // Log the entire context for debugging
             // ... (rest of the error handling logic) ...
         }

    2. Environment-Specific Configuration (Echo-Specific): Use environment variables to determine whether to use the custom e.HTTPErrorHandler (production) or Echo's default handler (development).
    3. Review HTTPError Usage (Echo-Specific): Review all instances where echo.NewHTTPError() is used. Ensure that the error messages and status codes do not leak sensitive information that might be specific to Echo's internal workings.
    4. Consistent Error Format: Ensure all error responses have a consistent format.

  • Threats Mitigated:

    • Information Disclosure (Severity: Medium): Prevents attackers from gaining information about the application's internal workings, specifically information related to Echo's request handling, middleware, or routing.

  • Impact:

    • Information Disclosure: Risk reduced from Medium to Low.

  • Currently Implemented: Partially. A custom handler exists, but it doesn't consistently log the full echo.Context, and messages sometimes include internal details.

  • Missing Implementation:

    • Comprehensive logging of the echo.Context in the custom error handler.
    • Thorough review of all echo.NewHTTPError() usage.
    • Consistent error response format.

Mitigation Strategy: Secure File Upload Handling (If using Echo's features)

• Mitigation Strategy: Secure File Upload Handling (If using Echo's features)

  • Description:

    1. Limit File Size (Echo-Specific): Use e.Use(middleware.BodyLimit("2M")) to limit the maximum size of requests, including file uploads. This is an Echo-provided middleware.
    2. Validate File Type and Size (Echo-Specific):
       • Use c.FormFile("file") (an Echo function) to retrieve the uploaded file from the echo.Context.
       • Validate file type using magic numbers (as described previously), after retrieving the file using c.FormFile().
    3. Secure Storage and Malware Scanning (as described previously, but these are general security practices, not Echo-specific).
    4. Avoid Direct Execution (General security practice).

  • Threats Mitigated:

    • File Upload Vulnerabilities (Severity: Critical): Prevents attackers from uploading malicious files. The use of c.FormFile() is the Echo-specific aspect.
    • Directory Traversal (Severity: High): Secure storage practices (not Echo-specific).
    • Cross-Site Scripting (XSS) (Severity: High): Preventing upload of HTML/JS files (partially related to using c.FormFile() for retrieval).

  • Impact:

    • File Upload Vulnerabilities: Risk reduced from Critical to Low.
    • Directory Traversal: Risk reduced from High to Low.
    • XSS: Risk reduced from High to Low (in the context of file uploads).

  • Currently Implemented: None. File uploads are not currently handled.

  • Missing Implementation: All aspects of secure file upload handling, including the Echo-specific parts (middleware.BodyLimit and c.FormFile).