Summary
A critical OS command injection vulnerability in the login.xgi CGI endpoint of Iskratel Innbox GPON ONT devices may allow an unauthenticated remote attacker to execute arbitrary operating-system commands.
Successful exploitation can provide root-level control of the affected device when the endpoint is reachable and processes attacker-controlled CLI input without adequate separation or validation.
A critical OS command injection vulnerability in the login.xgi CGI endpoint of Iskratel Innbox GPON ONT devices may allow an unauthenticated remote attacker to execute arbitrary operating-system commands.
Successful exploitation can provide root-level control of the affected device when the endpoint is reachable and processes attacker-controlled CLI input without adequate separation or validation.
Affected context
The vulnerability occurs in Iskratel Innbox GPON ONT devices where the login.xgi CGI endpoint is exposed through a reachable management or web interface and accepts a CLI-related parameter. Risk is increased when the endpoint is accessible from an untrusted network and the device processes that parameter with root privileges without effective command and argument isolation.
The vulnerability occurs in Iskratel Innbox GPON ONT devices where the login.xgi CGI endpoint is exposed through a reachable management or web interface and accepts a CLI-related parameter. Risk is increased when the endpoint is accessible from an untrusted network and the device processes that parameter with root privileges without effective command and argument isolation.
Exploit preconditions
- Attack surface: The
login.xgiCGI endpoint on an Innbox GPON ONT device - Required access: No authentication may be required when the endpoint is reachable
- Trigger point: Processing of attacker-controlled data supplied through the CLI parameter
- Why exploitation is possible: The parameter is incorporated into operating-system command processing without sufficient separation between data and executable command syntax
- Privilege context: The affected service can execute commands with root-level privileges
- Attack surface: The
login.xgiCGI endpoint on an Innbox GPON ONT device - Required access: No authentication may be required when the endpoint is reachable
- Trigger point: Processing of attacker-controlled data supplied through the CLI parameter
- Why exploitation is possible: The parameter is incorporated into operating-system command processing without sufficient separation between data and executable command syntax
- Privilege context: The affected service can execute commands with root-level privileges
Why this happens
The underlying bug is an operating-system command injection flaw mapped to CWE-78. The CGI handler treats externally supplied parameter data as part of a shell or command invocation rather than as strictly bounded argument data, allowing input to alter the intended command behavior.
The lack of authentication on the endpoint also relates to CWE-306: Missing Authentication for Critical Function, because a security-sensitive operation may be reachable without verifying the caller's identity. Together, these conditions can expose a privileged command-execution path to unauthenticated network clients.
The underlying bug is an operating-system command injection flaw mapped to CWE-78. The CGI handler treats externally supplied parameter data as part of a shell or command invocation rather than as strictly bounded argument data, allowing input to alter the intended command behavior.
The lack of authentication on the endpoint also relates to CWE-306: Missing Authentication for Critical Function, because a security-sensitive operation may be reachable without verifying the caller's identity. Together, these conditions can expose a privileged command-execution path to unauthenticated network clients.
Potential impact
- An attacker may execute arbitrary commands on the affected ONT
- Device configuration and credentials could be modified
- Network traffic could be monitored, redirected, or disrupted
- The device may be used for persistence, lateral movement, or further attacks
- Availability of broadband or managed network services could be reduced
- An attacker may execute arbitrary commands on the affected ONT
- Device configuration and credentials could be modified
- Network traffic could be monitored, redirected, or disrupted
- The device may be used for persistence, lateral movement, or further attacks
- Availability of broadband or managed network services could be reduced
General mitigation guidance
Mitigation generally focuses on removing shell interpretation from request handling and protecting sensitive CGI functions behind strong access controls.
Common defensive patterns include:
- Passing fixed commands and separately validated arguments through APIs that do not invoke a shell
- Applying strict allowlists for expected CLI operations and parameter formats
- Requiring authentication and authorization for administrative endpoints
- Running request handlers with the least privileges necessary instead of root where feasible
- Restricting management interfaces to trusted networks and isolating them from the public internet
- Treating all request parameters as untrusted, including values received through internal management paths
Mitigation generally focuses on removing shell interpretation from request handling and protecting sensitive CGI functions behind strong access controls.
Common defensive patterns include:
- Passing fixed commands and separately validated arguments through APIs that do not invoke a shell
- Applying strict allowlists for expected CLI operations and parameter formats
- Requiring authentication and authorization for administrative endpoints
- Running request handlers with the least privileges necessary instead of root where feasible
- Restricting management interfaces to trusted networks and isolating them from the public internet
- Treating all request parameters as untrusted, including values received through internal management paths
How teams detect issues like this
Detection approaches may include:
- Static analysis for shell execution APIs that receive CGI parameters or other request-derived values
- Code review checks for string concatenation or interpolation in command construction
- Inventory and policy review of unauthenticated administrative CGI endpoints
- Dynamic testing that verifies command arguments remain data and cannot change execution structure
- Network monitoring for unusual requests to
login.xgi, unexpected administrative access, or outbound connections from ONT devices - Automated security review tools that flag command construction and missing endpoint authentication
Detection approaches may include:
- Static analysis for shell execution APIs that receive CGI parameters or other request-derived values
- Code review checks for string concatenation or interpolation in command construction
- Inventory and policy review of unauthenticated administrative CGI endpoints
- Dynamic testing that verifies command arguments remain data and cannot change execution structure
- Network monitoring for unusual requests to
login.xgi, unexpected administrative access, or outbound connections from ONT devices - Automated security review tools that flag command construction and missing endpoint authentication
Sources
| Source | Link |
|---|---|
| github. | github.com/ |
