CVE-2024-22938

Executive Summary

CVE-2024-22938 is a critical security vulnerability identified in BossCMS version 1.3.0. The issue stems from insecure permissions within the admin.class.php component, specifically in the init function. This flaw allows a local attacker to execute arbitrary code and escalate privileges, potentially leading to full system compromise. The vulnerability has a CVSS score of 0.0, indicating a lack of official scoring, but the impact is severe due to the potential for privilege escalation and code execution. No public proof-of-concept (PoC) or patch is currently available, making this a high-risk, unpatched vulnerability.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby ecosystems. It is a PHP-based CMS (BossCMS) vulnerability, and the risk is primarily to the application's own codebase and server environment.

CVSS Breakdown & Threat Level

The CVSS score is listed as 0.0, which is unusual and likely indicates that no official CVSS vector has been assigned. However, based on the description, the vulnerability involves local privilege escalation and arbitrary code execution. A reasonable estimated CVSS v3.1 vector would be:

• Attack Vector (AV): Local (L)
• Attack Complexity (AC): Low (L)
• Privileges Required (PR): Low (L)
• User Interaction (UI): None (N)
• Scope (S): Unchanged (U)
• Confidentiality (C): High (H)
• Integrity (I): High (H)
• Availability (A): High (H)

Estimated CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Estimated Base Score: 7.8 (High)

Threat Level: High. The vulnerability allows a local attacker with low privileges to gain full control of the system.

Deep Dive & Mechanics

The vulnerability resides in the init function of the admin.class.php component in BossCMS v1.3.0. The init function is typically called during the initialization of the admin panel. The insecure permissions issue likely means that the function does not properly validate the user's session or role before executing sensitive operations. This could allow an attacker with local access to the server (e.g., via a compromised low-privilege account) to call the init function with malicious parameters, leading to arbitrary code execution.

The exact mechanism is not publicly documented, but common patterns for such vulnerabilities include:

• Insecure Direct Object Reference (IDOR): The function may accept user-supplied parameters that control file paths or commands without proper sanitization.
• Missing Authorization Checks: The function may not verify that the caller has administrative privileges.
• Unsafe Deserialization: The function might deserialize user input without validation, leading to code execution.

Since no PoC is available, the exploitation details remain theoretical. However, the vulnerability is classified as CWE-732 (Incorrect Permission Assignment for Critical Resource), indicating that the software does not properly restrict access to a critical resource.

Vulnerable vs. Patched Code

No patched version is available. The vulnerable code is in admin.class.php within the init function. A hypothetical patch would involve:

• Adding proper session and role checks before executing sensitive operations.
• Sanitizing all user-supplied inputs.
• Implementing strict access controls.

Vulnerable Code (Hypothetical):

function init() {
    $action = $_GET['action'];
    // No permission check
    if ($action == 'execute') {
        system($_GET['cmd']);
    }
}

Patched Code (Hypothetical):

function init() {
    if (!isset($_SESSION['admin']) || $_SESSION['admin'] !== true) {
        die('Access denied');
    }
    $action = $_GET['action'];
    if ($action == 'execute') {
        $cmd = escapeshellcmd($_GET['cmd']);
        system($cmd);
    }
}

Exploitation & Lab Setup

Red Team (Attack Simulation)

Since no public exploit exists, a red team would need to craft a custom exploit. The attack would require local access to the BossCMS server.

1. Reconnaissance: Identify the BossCMS installation and locate the admin.class.php file.
2. Exploit Development: Analyze the init function to find injection points. For example, if the function uses include() or system() with user input, craft a payload.
3. Execution: Send a crafted HTTP request to the vulnerable endpoint.

Example Exploit (Hypothetical):

curl -X GET "http://target/admin/controller.php?action=init&cmd=id"

If the function executes the cmd parameter, the output of the id command will be returned.

Blue Team (Defense & Detection)

1. Monitor Logs: Look for unusual HTTP requests to admin endpoints, especially those with parameters like cmd, exec, or system.
2. File Integrity Monitoring: Monitor changes to admin.class.php and other critical files.
3. Access Control: Ensure that the web server runs with the least privileges necessary.
4. Web Application Firewall (WAF): Deploy rules to block suspicious parameters.

Indicators of Compromise (IOCs)

• File Path: /path/to/bosscms/admin/class/admin.class.php
• Suspicious HTTP Requests: GET requests to admin endpoints with parameters like cmd, exec, system, or action=init.
• System Commands: Unexpected execution of system commands (e.g., id, whoami, cat /etc/passwd).
• New User Accounts: Creation of new user accounts or modification of existing ones.
• Unusual Processes: Spawning of shells (e.g., /bin/sh, cmd.exe) from the web server process.

Detection Engineering

YARA Rule

rule CVE_2024_22938_BossCMS_Admin_Init
{
    meta:
        description = "Detects insecure permissions in BossCMS admin.class.php init function"
        author = "Valters IT"
        date = "2024-01-01"
        reference = "CVE-2024-22938"
    strings:
        $s1 = "function init" nocase
        $s2 = "admin.class.php" nocase
        $s3 = "system(" nocase
        $s4 = "exec(" nocase
        $s5 = "shell_exec(" nocase
    condition:
        all of ($s1, $s2) and any of ($s3, $s4, $s5)
}

Sigma Rule

title: CVE-2024-22938 BossCMS Admin Init Exploitation
id: 12345678-1234-1234-1234-123456789abc
status: experimental
description: Detects exploitation attempts of CVE-2024-22938 via HTTP requests to admin endpoints with suspicious parameters
author: Valters IT
date: 2024/01/01
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'GET'
        cs-uri-query|contains: 
            - 'action=init'
            - 'cmd='
            - 'exec='
            - 'system='
    condition: selection
falsepositives:
    - Legitimate admin actions (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2024-22938 BossCMS Admin Init Exploitation"; flow:to_server,established; content:"GET"; http_method; content:"action=init"; http_uri; content:"cmd="; http_uri; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate Action: Since no patch is available, the only mitigation is to restrict access to the BossCMS admin panel. Use firewall rules to allow only trusted IPs.
2. Code Review: Manually review admin.class.php and harden the init function by adding proper authorization checks and input sanitization.
3. Upgrade: Monitor for official patches from BossCMS. If none are released, consider migrating to a different CMS.
4. Least Privilege: Ensure the web server runs with minimal permissions. Do not run as root.
5. Web Application Firewall: Deploy WAF rules to block requests containing suspicious parameters like cmd, exec, or system.

Valters IT
DevSecOps & Cyber Threat Intelligence