mitigations.md

Mitigation Strategies Analysis for hangfireio/hangfire

Mitigation Strategy: Secure Hangfire Dashboard Access (Direct Hangfire Configuration)

• Description:

  1. Create Custom Authorization Filter: Implement a class that inherits from Hangfire.Dashboard.IAuthorizationFilter.
  2. Implement Authorize Method: Within the Authorize method:
     • Access the current HttpContext.
     • Retrieve the user's identity and roles/claims.
     • Check for authentication and required roles/claims (e.g., "HangfireAdmin"). Return true if authorized, false otherwise.
  3. Register the Filter: In your Hangfire configuration (e.g., Startup.cs):

     app.UseHangfireDashboard("/hangfire", new DashboardOptions
     {
         Authorization = new[] { new MyCustomHangfireAuthorizationFilter() }
     });

  4. Disable Dashboard (If Possible): If the dashboard is not strictly required in production, disable it entirely for maximum security. This is done by not calling app.UseHangfireDashboard().

• Threats Mitigated:

  • Unauthorized Access to Dashboard: (Severity: Critical) - Prevents unauthorized users from interacting with the Hangfire dashboard.
  • Malicious Job Execution (Indirectly): (Severity: Critical) - Reduces the attack surface for enqueuing malicious jobs via the dashboard.
  • Data Exfiltration (Indirectly): (Severity: High) - Reduces the risk of viewing sensitive job data through the dashboard.

• Impact:

  • Unauthorized Access to Dashboard: Risk reduced from Critical to Low (with a strong authorization filter).
  • Malicious Job Execution: Risk reduced from Critical to Medium.
  • Data Exfiltration: Risk reduced from High to Medium.

• Currently Implemented: (Fill this in - Examples:)

  • "Implemented with a custom IAuthorizationFilter and ASP.NET Core Identity."
  • "Dashboard is disabled in production."
  • "Not implemented."

• Missing Implementation: (Fill this in - Examples:)

  • "Need to implement role-based access control within the authorization filter."
  • "Need to disable the dashboard in the production environment."

Mitigation Strategy: Secure Job Serialization (Direct Hangfire Configuration)

• Description:

  1. Configure the Serializer: In your Hangfire configuration, explicitly configure the serializer settings. If using JSON.NET (the default):

     GlobalConfiguration.Configuration.UseSerializerSettings(new JsonSerializerSettings
     {
         TypeNameHandling = TypeNameHandling.Auto // Or a custom SerializationBinder
     });

  2. Avoid TypeNameHandling.All: Never use TypeNameHandling.All in a production environment, as it's highly vulnerable to deserialization attacks.
  3. Custom SerializationBinder (Recommended): For the highest level of security, implement a custom SerializationBinder to explicitly whitelist the types that are allowed to be deserialized:

     public class MyCustomSerializationBinder : ISerializationBinder
     {
         private readonly List<Type> _allowedTypes = new List<Type>
         {
             typeof(MyJobArgumentType1),
             typeof(MyJobArgumentType2),
             // ... add all allowed types here ...
         };
     
         public Type BindToType(string assemblyName, string typeName)
         {
             var type = Type.GetType($"{typeName}, {assemblyName}");
             if (type != null && _allowedTypes.Contains(type))
             {
                 return type;
             }
             return null; // Or throw an exception
         }
     
         public void BindToName(Type serializedType, out string assemblyName, out string typeName)
         {
             assemblyName = serializedType.Assembly.FullName;
             typeName = serializedType.FullName;
         }
     }
     
     // In your Hangfire configuration:
     GlobalConfiguration.Configuration.UseSerializerSettings(new JsonSerializerSettings
     {
         TypeNameHandling = TypeNameHandling.Objects, // Use Objects with a custom binder
         SerializationBinder = new MyCustomSerializationBinder()
     });

• Threats Mitigated:

  • Deserialization Vulnerabilities: (Severity: Critical) - Prevents attackers from injecting malicious payloads through the deserialization process.
  • Malicious Job Execution: (Severity: Critical) - Prevents the execution of arbitrary code injected via deserialization.

• Impact:

  • Deserialization Vulnerabilities: Risk reduced from Critical to Low (with a securely configured serializer and a custom SerializationBinder).
  • Malicious Job Execution: Risk reduced from Critical to Low (as a direct consequence of preventing deserialization attacks).

• Currently Implemented: (Fill this in - Examples:)

  • "Using TypeNameHandling.Auto."
  • "Using a custom SerializationBinder."
  • "Not explicitly configured; using the default settings."

• Missing Implementation: (Fill this in - Examples:)

  • "Need to implement a custom SerializationBinder."
  • "Need to switch from TypeNameHandling.All to TypeNameHandling.Auto."

Mitigation Strategy: Configure Job Concurrency and Queue Limits (Direct Hangfire Configuration)

• Description:

  1. Worker Count: Configure the number of worker threads that Hangfire uses to process jobs. This is typically done when configuring the Hangfire server:

      //Example for SQL Server
     GlobalConfiguration.Configuration.UseSqlServerStorage("connection_string", new SqlServerStorageOptions
     {
         //Example
         CommandBatchMaxTimeout = TimeSpan.FromMinutes(5),
         SlidingInvisibilityTimeout = TimeSpan.FromMinutes(5),
         QueuePollInterval = TimeSpan.Zero,
         UseRecommendedIsolationLevel = true,
         DisableGlobalLocks = true,
         MaxDegreeOfParallelism = 4 // Example concurrency limit - adjust as needed!
     });
     
     // Or, for a BackgroundJobServer:
     app.UseHangfireServer(new BackgroundJobServerOptions
     {
         WorkerCount = Environment.ProcessorCount * 5 // Example - adjust as needed!
     });

  2. Queue Limits: If using a storage provider that supports queue limits (e.g., Redis), configure limits on the number of jobs that can be enqueued in each queue. This prevents a single queue from being overwhelmed. This is storage-provider specific.
  3. Queue Prioritization: Use different queues for different job types and assign priorities. This is done when enqueuing jobs:

     BackgroundJob.Enqueue<IMyService>(x => x.MyMethod(), "high-priority"); // Enqueue to "high-priority" queue
     BackgroundJob.Enqueue<IMyService>(x => x.MyOtherMethod(), "default"); // Enqueue to "default" queue

     Then, configure your workers to process queues in priority order.

• Threats Mitigated:

  • Denial of Service (DoS): (Severity: High) - Prevents an attacker from overwhelming the system by enqueuing a massive number of jobs.
  • Resource Exhaustion: (Severity: Medium) - Prevents Hangfire from consuming excessive resources (CPU, memory, threads).

• Impact:

  • Denial of Service (DoS): Risk reduced from High to Medium (with appropriate concurrency and queue limits).
  • Resource Exhaustion: Risk reduced from Medium to Low.

• Currently Implemented: (Fill this in - Examples:)

  • "Worker count is set to the default."
  • "Worker count is configured based on the number of processor cores."
  • "Queue limits are not configured."
  • "Queue prioritization is used."

• Missing Implementation: (Fill this in - Examples:)

  • "Need to determine appropriate worker count based on load testing."
  • "Need to configure queue limits (if using Redis)."
  • "Need to implement queue prioritization."