CVE-2024-26294 - Critical RCE in ClearPass Policy Manager Web Interface — Deep Dive, PoC, and Exploit Analysis

CVE-2024-26294 is a severe security vulnerability discovered in Aruba’s ClearPass Policy Manager, a popular AAA solution used in networks worldwide. The flaw lurks in the web-based management interface and can let remote, authenticated attackers execute arbitrary system commands as root on the underlying OS. If exploited, this leads to complete system compromise. Here’s a simple technical breakdown, proof-of-concept code, mitigation advice, and links for further reading.

What Is ClearPass and Why This Matters

ClearPass Policy Manager is widely deployed for authentication, authorization, and policy enforcement. Breaching it can seriously undermine network security, letting attackers manipulate access, pivot further, or plant persistent malware.

Where’s the Bug?

The vulnerability lies in the web interface’s handling of user-supplied data, specifically in certain API endpoints. Unsanitized input is passed into system commands. Suppose a feature lets admins or users specify parameters — but forgets to filter out malicious characters.

Simplified Vulnerable Code (Hypothetical)

<?php
// Vulnerable PHP pseudo-code handling web requests

$user_input = $_POST['username'];
$password = $_POST['password'];
// Potential bad: unescaped use in a system call
system("/usr/bin/cp-user add $user_input $password");
?>

If no sanitization is performed, an attacker can inject additional shell commands into $user_input — classic Command Injection.

Attacker logs in to the web interface with valid user credentials.

2. Sends a crafted POST request to an affected endpoint, injecting OS commands with special shell characters (;, &&, |).

Assume the endpoint /api/user/add is vulnerable. Here’s a simple curl proof-of-concept

curl -k -u user:pass \
  -X POST \
  -d 'username=eviluser;id>/tmp/pwned.txt;' \
  -d 'password=notimportant' \
  'https://target-clearpass.local/api/user/add';

This would run id as root and put the output in /tmp/pwned.txt.

Real-World Impact

- Full root control over the system to install tools, create new admin users, or hide malicious processes.

Affected Versions

> See Aruba’s Security Advisory:
> ARUBA-PSA-2024-005

ClearPass Policy Manager versions *prior* to the patched releases noted in the PSA are susceptible. Always check your deployment.

Detection and Mitigation

To check for compromise:

To mitigate

- Upgrade ClearPass Policy Manager *immediately* to the latest version from Aruba Support Portal.

Add strict input validation to affected endpoints. If using PHP, for instance

if (!preg_match('/^[a-zA-Z-9_-]+$/', $user_input)) {
    die('Invalid username!');
}

Responsible Disclosure and References

- CVE-2024-26294 NVD Entry
- Aruba’s Official Security Advisory
- ClearPass Documentation

Conclusion

CVE-2024-26294 is a textbook example of why input validation is crucial, especially in privileged network appliances. If you run Aruba ClearPass, act swiftly to patch or upgrade, change passwords, and audit logs.

Timeline

Published on: 02/27/2024 22:15:14 UTC
Last modified on: 02/28/2024 14:06:45 UTC