CVE-2026-23813

Executive Summary

CVE-2026-23813 is a critical authentication bypass vulnerability in the web-based management interface of Aruba AOS-CX switches. With a CVSS score of 9.8, an unauthenticated remote attacker can circumvent existing authentication controls, potentially resetting the admin password and gaining full administrative control over the affected switch. No public exploit code or proof-of-concept is currently available, and no patch has been released. The vulnerability is classified under CWE-306 (Missing Authentication for Critical Function). Immediate mitigation measures are required, including network segmentation and strict access controls.

CVSS Breakdown & Threat Level

• CVSS Score: 9.8 (Critical)
• Attack Vector: Network (AV:N)
• Attack Complexity: Low (AC:L)
• Privileges Required: None (PR:N)
• User Interaction: None (UI:N)
• Scope: Unchanged (S:U)
• Confidentiality Impact: High (C:H)
• Integrity Impact: High (I:H)
• Availability Impact: High (A:H)
• Exploitability: Low (no public exploit, but high impact)
• Threat Level: Critical – immediate action required.

Deep Dive & Mechanics

The vulnerability resides in the web-based management interface of Aruba AOS-CX switches. The interface fails to properly authenticate requests to certain endpoints, allowing an unauthenticated remote attacker to send crafted HTTP requests that bypass authentication checks. In some cases, this can trigger a password reset for the admin account, granting full administrative access. The root cause is a missing authentication check (CWE-306) on critical functions such as password reset or user management APIs.

The attack does not require any prior knowledge or credentials. The attacker only needs network access to the management interface (typically TCP port 443 or 80). Once exploited, the attacker can modify switch configurations, intercept network traffic, or pivot to other internal systems.

Vulnerable vs. Patched Code

No patch is currently available. The vulnerable code likely involves a function that handles password reset requests without verifying the session or authentication token. A patched version would require implementing proper authentication checks, such as verifying a valid session cookie or API token before allowing password reset operations.

Vulnerable code (pseudo):

def reset_password(request):
    # No authentication check
    new_password = request.POST.get('new_password')
    admin_user = User.objects.get(username='admin')
    admin_user.set_password(new_password)
    admin_user.save()
    return HttpResponse("Password reset successful")

Patched code (pseudo):

def reset_password(request):
    if not request.user.is_authenticated:
        return HttpResponseForbidden("Authentication required")
    if not request.user.is_admin:
        return HttpResponseForbidden("Admin privileges required")
    new_password = request.POST.get('new_password')
    admin_user = User.objects.get(username='admin')
    admin_user.set_password(new_password)
    admin_user.save()
    return HttpResponse("Password reset successful")

Exploitation & Lab Setup

Red Team

Lab Setup:

• Target: Aruba AOS-CX switch (e.g., 6300F, 6400, 8320 series) with management interface exposed.
• Attacker: Kali Linux or any system with network access to the switch management IP.
• Tools: curl, Burp Suite, or custom Python script.

Exploitation Steps:

1. Identify the management interface IP and port (default 443).
2. Send a crafted HTTP POST request to the password reset endpoint (e.g., /reset_password or /api/password/reset).
3. Include parameters such as new_password and possibly username=admin.
4. If successful, the admin password is changed, and the attacker can log in with the new password.

Example curl command:

curl -k -X POST https://<switch-ip>/reset_password -d "new_password=Hacked123!"

Note: No public exploit code is available; this is a hypothetical exploitation scenario based on the vulnerability description.

Blue Team

Detection & Prevention:

• Monitor for unusual HTTP requests to management interface endpoints, especially POST requests to password reset or user management URLs.
• Implement network segmentation: restrict management interface access to trusted IPs only (e.g., via ACLs or firewall rules).
• Enable logging and alerting for authentication failures and password changes.
• Use a Web Application Firewall (WAF) to block requests to sensitive endpoints without proper authentication tokens.
• Regularly review switch logs for unauthorized access attempts.

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP POST requests to /reset_password, /api/password/reset, or similar endpoints from untrusted IPs.
  • Successful login from an unknown IP after a password reset event.
• System IOCs:
  • Unexpected changes to the admin password.
  • New user accounts or privilege escalations in switch logs.
  • Unusual configuration changes (e.g., SNMP community strings, VLAN modifications).
• Log IOCs:
  • Log entries showing password reset without prior authentication.
  • Repeated failed login attempts followed by a successful login from a different IP.

Detection Engineering

YARA Rule

rule CVE_2026_23813_Aruba_AOS_CX_Auth_Bypass {
    meta:
        description = "Detects exploitation attempts for CVE-2026-23813 in Aruba AOS-CX switches"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-23813"
    strings:
        $s1 = "reset_password" ascii wide nocase
        $s2 = "new_password" ascii wide nocase
        $s3 = "admin" ascii wide nocase
    condition:
        any of ($s1, $s2, $s3)
}

Sigma Rule

title: Aruba AOS-CX Authentication Bypass Attempt
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects HTTP POST requests to password reset endpoints on Aruba AOS-CX switches without prior authentication.
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: aruba
detection:
    selection:
        cs-method: 'POST'
        cs-uri-stem:
            - '/reset_password'
            - '/api/password/reset'
            - '/password/reset'
    condition: selection
falsepositives:
    - Legitimate password reset requests from authorized administrators (should be rare)
level: high

Suricata Rule

alert http $EXTERNAL_NET any -> $HOME_NET $HTTP_PORTS (msg:"CVE-2026-23813 Aruba AOS-CX Authentication Bypass Attempt"; flow:to_server,established; content:"POST"; http_method; content:"/reset_password"; http_uri; nocase; content:"new_password"; http_client_body; nocase; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Network Segmentation: Restrict access to the management interface to trusted administrative networks only. Use ACLs or firewall rules to block external access.
2. Disable Management Interface: If not required, disable the web-based management interface and use CLI via SSH or console.
3. Monitor Logs: Enable detailed logging and monitor for suspicious activity, especially password reset events.
4. Apply Workarounds: If available, apply vendor-recommended workarounds (e.g., disabling specific services or endpoints).

Long-term Actions:

1. Patch: Apply the official patch as soon as it is released by Aruba.
2. Upgrade: Upgrade to a patched version of AOS-CX when available.
3. Review Security Posture: Conduct a security audit of all network devices and implement least-privilege access controls.
4. Incident Response: Prepare an incident response plan for potential exploitation of this vulnerability.

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