Summary
A critical OS command injection vulnerability affects the CGI handler of the Netcore NR289-GE through the ip argument processed by /ap_ip.cgi. A remote attacker may be able to execute operating-system commands when the exposed endpoint is reachable and accepts insufficiently validated input.
Affected context
The vulnerability occurs in Netcore NR289-GE 1.4.5102 deployments where the CGI handler exposes /ap_ip.cgi and uses the ip argument in a system command or command-like operation. Risk is elevated when the management interface is remotely reachable, the endpoint lacks strong authentication or authorization, and supplied values are not strictly constrained to expected IP-address formats.
Exploit preconditions
- Attack surface: The remotely reachable
/ap_ip.cgiCGI endpoint - Required access: Network reachability and any authentication or authorization access imposed by the device
- Trigger point: Processing of the
ipargument by the CGI handler - Why exploitation is possible: User-controlled input may reach an operating-system command without adequate separation, validation, or escaping
Why this happens
The underlying bug is the unsafe incorporation of externally supplied data into an operating-system command. If the handler constructs or invokes a command using the ip argument without strict allowlisting and safe argument handling, command metacharacters or unexpected syntax may alter the intended operation. 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 Command describing the broader command-injection class.
Potential impact
- An attacker may execute arbitrary commands with the privileges of the CGI service
- The device could be taken over or rendered unavailable
- Network configuration, credentials, or operational data could be exposed
- The device could be used to attack other systems on reachable networks
- Persistent compromise or malicious configuration changes could occur
General mitigation guidance
Mitigation generally focuses on removing shell interpretation from request-processing paths and reducing trust in network-provided values.
Common defensive patterns include:
- Use dedicated networking and system APIs instead of shell commands
- Pass arguments through structured, non-shell interfaces where subprocess use is unavoidable
- Apply strict allowlist validation for IP-address values and reject unexpected syntax
- Enforce authentication, authorization, and network isolation for management endpoints
- Run CGI services with the least privileges and restrict access to sensitive device functions
- Apply compensating controls such as gateway filtering and administrative-interface segmentation
How teams detect issues like this
Organizations can look for command-injection risks through:
- Static analysis targeting shell invocation, command-construction functions, and concatenation of request parameters
- Code review checks for CGI parameters flowing into system, exec, or equivalent APIs
- Dynamic testing with benign invalid input and monitoring for unexpected process creation
- Web and device logs showing unusual requests to
/ap_ip.cgior malformedipvalues - Policy enforcement requiring allowlist validation and prohibiting shell use in network-facing handlers
Automated code review and software composition tools may help identify related unsafe command-execution patterns.
