Skip to content

Latest commit

 

History

History
43 lines (36 loc) · 6.2 KB

threat-modeling.md

File metadata and controls

43 lines (36 loc) · 6.2 KB

Threat Model Analysis for reactivex/rxdart

Threat: Uncontrolled Stream Emission (DoS)

  • Description: An attacker manipulates a data source (e.g., a compromised sensor, a malicious network connection, or even flawed application logic that directly interacts with an RxDart Subject) to cause an RxDart stream to emit an excessive number of events or excessively large data payloads in a short period. This overwhelms the application's processing capacity. The key here is the direct interaction with an RxDart component that allows for uncontrolled emission.
  • Impact: Denial of Service (DoS). The application becomes unresponsive, crashes, or consumes excessive resources (CPU, memory, network bandwidth), making it unavailable to legitimate users.
  • RxDart Component Affected: Any Stream source, particularly Subject variants (PublishSubject, BehaviorSubject, ReplaySubject) if they are exposed to external input or are fed by uncontrolled logic and the attacker can directly call add, addError, or addStream on them. Also affects any downstream operators that don't implement backpressure.
  • Risk Severity: High to Critical (depending on the application's criticality and the ease of triggering the attack).
  • Mitigation Strategies:
    • Backpressure Operators: Use RxDart operators designed for flow control:
      • debounce(Duration): Emit only the last item after a specified quiet period.
      • throttle(Duration): Emit the first item, then ignore subsequent items for a specified duration.
      • buffer(Stream) or bufferTime(Duration): Collect items into a list and emit the list periodically.
      • window(Stream) or windowTime(Duration): Similar to buffer, but emits a Stream of items instead of a list.
      • sample(Stream) or sampleTime(Duration): Emit the most recent item at a regular interval.
    • Input Validation (at the point of Subject interaction): Rigorously validate all data before it is added to a Subject using add, addError, or addStream. This includes validating the rate and size of data.
    • Rate Limiting (if controlling the Subject): If the application logic directly controls the Subject, implement rate limiting before adding data to the Subject.
    • Timeout Operator: Use the timeout(Duration) operator to prevent the stream from hanging indefinitely if a source stops emitting or becomes unresponsive. This is particularly important for streams that rely on external data sources.

Threat: Sensitive Data Exposure Through Streams

  • Description: Sensitive data (passwords, API keys, personal information) is inadvertently passed through an RxDart stream that is exposed to unauthorized parties. This could happen through logging, debugging tools, or a compromised subscriber if the stream itself is not properly protected. The focus here is on the RxDart stream as the conduit for the leak.
  • Impact: Information Disclosure. Sensitive data is leaked, potentially leading to identity theft, financial loss, or privacy violations.
  • RxDart Component Affected: Any Stream carrying sensitive data, and any operators that process or transform that data. The vulnerability lies in the unintentional exposure of the stream itself.
  • Risk Severity: Critical.
  • Mitigation Strategies:
    • Data Sanitization/Redaction: Transform or redact sensitive data before it enters the stream. For example, replace passwords with placeholders or hash API keys. This is the primary mitigation.
    • Avoid Unnecessary Exposure: Don't pass sensitive data through streams unless absolutely necessary.
    • Controlled Subscriptions: Carefully control who can subscribe to streams that might contain sensitive data. Avoid exposing such streams globally or to untrusted components. This is about limiting access to the stream.
    • Secure Logging: If logging stream data (which should be avoided for sensitive streams), ensure that sensitive information is masked, encrypted, or omitted from the logs. Use a secure logging framework and never log the raw stream contents if they might contain sensitive data.
    • Disable Debugging in Production: Remove or disable any debugging code that might expose stream contents (e.g., printing stream values to the console) in a production environment.

Threat: Stream Source Spoofing (Direct Subject Manipulation)

  • Description: An attacker gains direct access to an RxDart Subject (e.g., PublishSubject, BehaviorSubject, ReplaySubject) and uses its add, addError, or addStream methods to inject fabricated data or errors. This differs from general input validation issues; it requires the attacker to be able to directly call methods on the Subject instance.
  • Impact: Spoofing/Tampering. The application behaves incorrectly based on the false data, potentially leading to security vulnerabilities, incorrect decisions, or data corruption.
  • RxDart Component Affected: Subject variants (PublishSubject, BehaviorSubject, ReplaySubject) where the attacker can directly call add, addError, or addStream.
  • Risk Severity: High to Critical (depending on the sensitivity of the data and the consequences of incorrect behavior).
  • Mitigation Strategies:
    • Restrict Subject Access: Do not expose Subject instances directly to untrusted code. This is the most crucial mitigation. Instead, expose only the Stream part of the Subject (using subject.stream) to consumers. This prevents external code from directly adding data.
    • Internal Validation (within the Subject's owner): If a component owns a Subject and adds data to it, that component should rigorously validate the data before adding it. This acts as a second layer of defense.
    • Consider Alternatives to Subjects: If possible, use alternative stream creation methods that don't involve mutable Subject instances, such as Stream.fromIterable, Stream.fromFuture, or custom stream controllers with limited exposure.