Summary
SmsForwarder through version 3.5.0 exposes remote-control APIs through its AndServer HTTP server without requiring authentication. An unauthenticated network attacker may read sensitive data, send SMS messages, and export or overwrite application configuration when the default-enabled endpoints are reachable.
SmsForwarder through version 3.5.0 exposes remote-control APIs through its AndServer HTTP server without requiring authentication. An unauthenticated network attacker may read sensitive data, send SMS messages, and export or overwrite application configuration when the default-enabled endpoints are reachable.
Affected context
The vulnerability occurs in SmsForwarder deployments that expose the embedded AndServer HTTP service and leave its remote-control endpoints enabled without an effective authentication requirement. Risk depends on network reachability, endpoint configuration, and whether the service is accessible beyond a trusted local environment.
The vulnerability occurs in SmsForwarder deployments that expose the embedded AndServer HTTP service and leave its remote-control endpoints enabled without an effective authentication requirement. Risk depends on network reachability, endpoint configuration, and whether the service is accessible beyond a trusted local environment.
Exploit preconditions
- Attack surface: The AndServer HTTP service and its remote-control API endpoints
- Required access: Network connectivity to the exposed HTTP server; valid credentials are not required
- Trigger point: Direct requests to default-enabled APIs, including SMS, call-log, contact, and clone operations
- Why exploitation is possible: The server accepts sensitive and state-changing requests without verifying the caller's identity or authorization
- Attack surface: The AndServer HTTP service and its remote-control API endpoints
- Required access: Network connectivity to the exposed HTTP server; valid credentials are not required
- Trigger point: Direct requests to default-enabled APIs, including SMS, call-log, contact, and clone operations
- Why exploitation is possible: The server accepts sensitive and state-changing requests without verifying the caller's identity or authorization
Why this happens
The underlying flaw is a missing authentication control on security-sensitive HTTP endpoints. The application exposes remote-control functionality without consistently requiring callers to prove their identity before accessing data or performing state-changing operations. This maps to CWE-306: Missing Authentication for Critical Function, because critical functions can be invoked by unauthenticated users.
The underlying flaw is a missing authentication control on security-sensitive HTTP endpoints. The application exposes remote-control functionality without consistently requiring callers to prove their identity before accessing data or performing state-changing operations. This maps to CWE-306: Missing Authentication for Critical Function, because critical functions can be invoked by unauthenticated users.
Potential impact
- Attackers may read SMS messages, call logs, and contacts
- Unauthorized users may send SMS messages from the device
- Configuration data may be exported or overwritten
- Attackers could alter application behavior or persistence settings
- Exposed personal and communications data could be used for surveillance, fraud, or further compromise
- Attackers may read SMS messages, call logs, and contacts
- Unauthorized users may send SMS messages from the device
- Configuration data may be exported or overwritten
- Attackers could alter application behavior or persistence settings
- Exposed personal and communications data could be used for surveillance, fraud, or further compromise
General mitigation guidance
Mitigation generally focuses on placing strong identity and authorization checks in front of every remote-control endpoint.
Common defensive patterns include:
- Require authentication by default for all HTTP management and control APIs
- Apply endpoint-level authorization based on least privilege
- Disable remote-control interfaces that are not required
- Bind administrative services only to trusted interfaces or protected networks
- Use secure transport and avoid relying on network location as the sole trust boundary
- Validate that clone, export, messaging, and configuration operations require explicit authorization
- Minimize the sensitive data and device capabilities available to each API identity
Mitigation generally focuses on placing strong identity and authorization checks in front of every remote-control endpoint.
Common defensive patterns include:
- Require authentication by default for all HTTP management and control APIs
- Apply endpoint-level authorization based on least privilege
- Disable remote-control interfaces that are not required
- Bind administrative services only to trusted interfaces or protected networks
- Use secure transport and avoid relying on network location as the sole trust boundary
- Validate that clone, export, messaging, and configuration operations require explicit authorization
- Minimize the sensitive data and device capabilities available to each API identity
How teams detect issues like this
Detection can include static analysis and code review for HTTP routes that invoke sensitive operations without authentication or authorization middleware. Reviewers can inspect default server configuration, route registration, and handler call paths for SMS, contact, call-log, export, and configuration-modification functions.
Runtime monitoring can alert on unauthenticated requests, unexpected access to management endpoints, unusual outbound SMS activity, and configuration changes. Policy enforcement may include API gateway authentication requirements, network exposure rules, endpoint inventory checks, and automated tests confirming that protected routes reject unauthenticated requests.
Detection can include static analysis and code review for HTTP routes that invoke sensitive operations without authentication or authorization middleware. Reviewers can inspect default server configuration, route registration, and handler call paths for SMS, contact, call-log, export, and configuration-modification functions.
Runtime monitoring can alert on unauthenticated requests, unexpected access to management endpoints, unusual outbound SMS activity, and configuration changes. Policy enforcement may include API gateway authentication requirements, network exposure rules, endpoint inventory checks, and automated tests confirming that protected routes reject unauthenticated requests.
