A vulnerability in the CLI of Cisco FXOS Software and Cisco NX-OS Software could allow an authenticated, local attacker to execute arbitrary commands on the underlying Linux operating system with the privilege level of root. The vulnerability is due to insufficient validation of arguments passed to a specific CLI command on the affected device. An attacker could exploit this vulnerability by including malicious input as the argument of an affected command. A successful exploit could allow the attacker to execute arbitrary commands on the underlying Linux operating system with elevated privileges. An attacker would need valid administrator credentials to exploit this vulnerability.
The product constructs a string for a command to be executed by a separate component in another control sphere, but it does not properly delimit the intended arguments, options, or switches within that command string.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Nx-os | Cisco | * | 8.2(3) (excluding) |
| Nx-os | Cisco | 8.3 (including) | 8.3(1) (excluding) |
When creating commands using interpolation into a string, developers may assume that only the arguments/options that they specify will be processed. This assumption may be even stronger when the programmer has encoded the command in a way that prevents separate commands from being provided maliciously, e.g. in the case of shell metacharacters. When constructing the command, the developer may use whitespace or other delimiters that are required to separate arguments when the command. However, if an attacker can provide an untrusted input that contains argument-separating delimiters, then the resulting command will have more arguments than intended by the developer. The attacker may then be able to change the behavior of the command. Depending on the functionality supported by the extraneous arguments, this may have security-relevant consequences.