Summary
A critical OS command injection vulnerability affects the Linksys E1700 router's DMZ configuration handler. An attacker who can send crafted remote requests to the exposed management endpoint may cause the device to execute operating-system commands.
A critical OS command injection vulnerability affects the Linksys E1700 router's DMZ configuration handler. An attacker who can send crafted remote requests to the exposed management endpoint may cause the device to execute operating-system commands.
Affected context
The weakness occurs in the Linksys E1700 firmware version 1.0.0.4.003, within the /goform/setDMZ handler that processes the MAC_addr argument. Risk is increased when the router's administrative interface is reachable by an untrusted remote party and the parameter is incorporated into an operating-system command without sufficient validation or safe execution boundaries.
The weakness occurs in the Linksys E1700 firmware version 1.0.0.4.003, within the /goform/setDMZ handler that processes the MAC_addr argument. Risk is increased when the router's administrative interface is reachable by an untrusted remote party and the parameter is incorporated into an operating-system command without sufficient validation or safe execution boundaries.
Exploit preconditions
- Attack surface: The router's HTTP management interface and
/goform/setDMZendpoint - Required access: Network reachability to the endpoint; authentication requirements depend on the device's administrative access controls
- Trigger point: Processing of the
MAC_addrparameter by thesetDMZfunction - Why exploitation is possible: Input appears to reach an operating-system command execution path without adequate separation between data and command syntax
- Attack surface: The router's HTTP management interface and
/goform/setDMZendpoint - Required access: Network reachability to the endpoint; authentication requirements depend on the device's administrative access controls
- Trigger point: Processing of the
MAC_addrparameter by thesetDMZfunction - Why exploitation is possible: Input appears to reach an operating-system command execution path without adequate separation between data and command syntax
Why this happens
The underlying issue is command construction or invocation that treats externally supplied parameter data as part of an operating-system command. If metacharacters or other control syntax are not rejected and the command is not invoked through a safe argument-based interface, an attacker may influence command interpretation. This maps primarily to CWE-78: Improper Neutralization of Special Elements used in an OS Command, with CWE-77: Improper Neutralization of Special Elements in Output Used by a Downstream Component describing the broader command-injection class.
The underlying issue is command construction or invocation that treats externally supplied parameter data as part of an operating-system command. If metacharacters or other control syntax are not rejected and the command is not invoked through a safe argument-based interface, an attacker may influence command interpretation. This maps primarily to CWE-78: Improper Neutralization of Special Elements used in an OS Command, with CWE-77: Improper Neutralization of Special Elements in Output Used by a Downstream Component describing the broader command-injection class.
Potential impact
- An attacker may execute arbitrary commands with the privileges of the router service
- Device configuration and network-routing behavior could be altered
- Credentials, network metadata, or stored configuration data could be exposed
- The router could be used to monitor, redirect, or disrupt network traffic
- A compromised device could support further attacks against connected systems
- An attacker may execute arbitrary commands with the privileges of the router service
- Device configuration and network-routing behavior could be altered
- Credentials, network metadata, or stored configuration data could be exposed
- The router could be used to monitor, redirect, or disrupt network traffic
- A compromised device could support further attacks against connected systems
General mitigation guidance
Mitigation generally focuses on keeping user-controlled values out of shell command interpretation and reducing the privileges available to network-facing services.
Common defensive patterns include:
- Replacing shell command construction with fixed operations and safe, argument-based APIs
- Applying strict allowlist validation for MAC-address input according to a canonical format
- Rejecting unexpected encoding, separators, and control characters before processing
- Limiting administrative interfaces to trusted management networks or secure access paths
- Running management services with the minimum privileges required
- Applying network segmentation and restricting outbound access from the device where feasible
Mitigation generally focuses on keeping user-controlled values out of shell command interpretation and reducing the privileges available to network-facing services.
Common defensive patterns include:
- Replacing shell command construction with fixed operations and safe, argument-based APIs
- Applying strict allowlist validation for MAC-address input according to a canonical format
- Rejecting unexpected encoding, separators, and control characters before processing
- Limiting administrative interfaces to trusted management networks or secure access paths
- Running management services with the minimum privileges required
- Applying network segmentation and restricting outbound access from the device where feasible
How teams detect issues like this
Organizations can look for command-injection risks through:
- Static analysis that identifies shell execution APIs receiving request parameters
- Code review of form handlers, CGI endpoints, and firmware management functions
- Tests that verify strict input validation and safe argument separation
- Monitoring for unusual administrative requests, configuration changes, process activity, or outbound connections
- Policy enforcement that prevents internet exposure of router management interfaces
- Automated security review tools that flag data flows from HTTP parameters into command interpreters
Organizations can look for command-injection risks through:
- Static analysis that identifies shell execution APIs receiving request parameters
- Code review of form handlers, CGI endpoints, and firmware management functions
- Tests that verify strict input validation and safe argument separation
- Monitoring for unusual administrative requests, configuration changes, process activity, or outbound connections
- Policy enforcement that prevents internet exposure of router management interfaces
- Automated security review tools that flag data flows from HTTP parameters into command interpreters
Sources
| Source | Link |
|---|---|
| github. | github.com/ |
| vuldb. | vuldb.com/ |
| vuldb. | vuldb.com/ |
| vuldb. | vuldb.com/ |
| vuldb. | vuldb.com/ |
| linksys. | linksys.com/ |
