Summary
A critical OS command injection vulnerability affects the Web Management Interface of the Netcore NBR200V2. An attacker who can reach the affected network-tools endpoint may manipulate the QUERY_STRING argument to cause unauthorized operating-system command execution.
Affected context
The vulnerability occurs in the Web Management Interface, specifically the
/www/cgi-bin/network_tools component, when the QUERY_STRING argument is
incorporated into an eval-based execution path. Risk is highest when the
interface is remotely reachable and request parameters are processed without
strict separation between data and commands.
Exploit preconditions
- Attack surface: Web Management Interface exposed over a reachable network
- Required access: Ability to submit requests to the affected endpoint; authentication requirements may depend on device configuration
- Trigger point: Processing of the
QUERY_STRINGargument by the network-tools functionality - Why exploitation is possible: User-controlled input reaches an
evalor operating-system command execution context without adequate validation, neutralization, or parameter separation
Why this happens
The underlying issue is command construction or evaluation using data that can be
influenced by an HTTP request. Passing insufficiently constrained input into an
eval-style execution path can allow control characters or command syntax to be
interpreted as executable instructions rather than ordinary data. This maps
primarily to CWE-78: Improper Neutralization of Special Elements used in an OS Command, with CWE-77: Improper Neutralization of Special Elements used in a Command describing the broader command-injection class.
Potential impact
- An attacker may execute unauthorized commands with the privileges of the web-management process.
- The device could be taken over or its configuration could be altered.
- Sensitive device, network, or administrative information could be exposed.
- The device could be used to disrupt services, establish persistence, or attack connected systems.
- Compromise could support broader network intrusion or botnet enrollment.
General mitigation guidance
Mitigation generally focuses on removing command evaluation from request
handling and reducing trust in all externally supplied parameters.
Common defensive patterns include:
- Replacing shell or
evalexecution with direct library or API calls. - Using fixed command mappings and strongly typed parameters instead of constructing commands from strings.
- Applying allowlists, canonicalization, and strict length and format validation at the boundary.
- Separating arguments from executable commands and avoiding shell interpretation where process execution is unavoidable.
- Restricting management interfaces to trusted administrative networks and enforcing least privilege for web services.
- Limiting the device account's filesystem, process, and network permissions.
- Recording and reviewing administrative requests, command errors, and unusual management-interface activity.
How teams detect issues like this
Detection approaches may include:
- Static analysis rules for
eval, shell invocation, command concatenation, and request parameters flowing into process-execution APIs. - Code review checks for
QUERY_STRINGor other HTTP inputs reaching interpreters without a strict allowlist. - Dynamic testing that verifies metacharacters and unexpected parameter formats are rejected without executing commands.
- Web-application firewall or gateway policies that restrict access to management endpoints and flag anomalous request parameters.
- Runtime monitoring for unexpected child processes, command interpreters, configuration changes, or outbound connections from the management service.
- Automated security review tools can help identify data flows from HTTP input to command-execution sinks.
