Summary
A high-severity command injection flaw in the H3C NX15 WAN API allows remotely supplied input to influence command execution through the workMode argument. An attacker who can reach the affected API may execute unauthorized commands on the device when crafted input is processed by the IPv6 WAN configuration function.
Affected context
The vulnerability occurs in H3C NX15 devices running the affected software release when the /api/esps endpoint processes requests for esps.ipv6.wan. Risk is present where the endpoint is remotely reachable and the workMode value is incorporated into an operating-system command without adequate separation from executable syntax.
Exploit preconditions
- Attack surface: Network-accessible H3C NX15 management or service API
- Required access: Ability to send requests to the affected
/api/espsfunctionality; authentication requirements depend on device configuration - Trigger point: Processing of the
workModeargument by theesps.ipv6.wanfunction - Why exploitation is possible: User-controlled input can reach command execution logic without sufficient validation, filtering, or safe argument handling
Why this happens
The underlying issue is improper neutralization of special elements in externally supplied input before that input is used in an operating-system command. This behavior maps primarily to CWE-77: Improper Neutralization of Special Elements used in a Command, with CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component describing the broader injection class. The insecure pattern occurs when application data is concatenated into shell commands or interpreted by a command processor instead of being passed as strictly separated arguments.
Potential impact
- An attacker may execute unauthorized commands on the network device
- Device configuration or operational data could be modified
- The device may be disrupted or rendered unavailable
- Credentials, secrets, or network information could be exposed
- A compromised device could support further movement within connected networks
General mitigation guidance
Mitigation generally focuses on removing shell interpretation from request-processing paths and reducing trust in client-controlled values.
Common defensive patterns include:
- Replacing shell command construction with direct, non-shell APIs
- Passing parameters through structured argument interfaces rather than string concatenation
- Allowing only narrowly defined values for fields such as
workMode - Applying server-side schema validation before invoking system operations
- Restricting management interfaces to trusted networks and enforcing least privilege
- Separating device service privileges from broader operating-system permissions
- Logging rejected input and anomalous requests without recording sensitive data
How teams detect issues like this
Organizations can look for this class of issue through:
- Static analysis rules that identify user-controlled data flowing into shell execution or command-spawning functions
- Code review checks for string concatenation, interpolation, or format operations used to build commands
- Tests that verify invalid and metacharacter-containing values are rejected before system calls
- API gateway policies restricting management endpoints and validating enumerated parameters
- Runtime monitoring for unexpected commands, process creation, or unusual requests to
/api/esps
Neutral automated code-review and software composition tools may help identify command-construction patterns, but their findings should be validated against the device's actual execution flow.
