CVE-2025-52998: Chamilo LMS RCE Vulnerability

CVE-2025-52998 Overview

CVE-2025-52998 is an insecure deserialization vulnerability affecting Chamilo, an open-source learning management system (LMS). Prior to version 1.11.30, the application performs deserialization of data that can be spoofed by an attacker. This flaw allows a malicious actor to create objects of arbitrary classes and fully control their properties, enabling modification of the web application's operation logic.

Critical Impact

Attackers with high-privileged access can exploit insecure deserialization to manipulate application behavior, potentially leading to data integrity compromise and service availability disruption.

Affected Products

• Chamilo LMS versions prior to 1.11.30
• chamilo chamilo_lms (cpe:2.3:a:chamilo:chamilo_lms:*:*:*:*:*:*:*:*)

Discovery Timeline

• 2026-03-02 - CVE CVE-2025-52998 published to NVD
• 2026-03-03 - Last updated in NVD database

Technical Details for CVE-2025-52998

Vulnerability Analysis

This vulnerability falls under CWE-502 (Deserialization of Untrusted Data), a well-known class of security issues that can lead to severe consequences. The flaw exists in the VChamilo plugin import functionality where user-controlled data is deserialized without adequate validation. An attacker can craft malicious serialized objects that, when deserialized by the application, instantiate arbitrary classes with attacker-controlled properties.

The attack is network-accessible and requires no user interaction, though it does necessitate high-privileged access to the vulnerable endpoint. Successful exploitation can result in limited confidentiality and integrity impact, but may cause high availability impact through denial of service or application disruption.

Root Cause

The root cause lies in the application's handling of file path validation within the VChamilo plugin import functionality. The original implementation performed case-sensitive validation for phar:// wrapper detection, which could be bypassed using case variations. Additionally, the deserialization mechanism did not adequately sanitize or validate the serialized data before processing, allowing injection of malicious object properties.

Attack Vector

The vulnerability is exploitable over the network by an authenticated attacker with elevated privileges. The attack involves:

1. Accessing the VChamilo plugin import functionality
2. Crafting a malicious request containing spoofed serialized data or using case-variant phar:// wrappers to bypass validation
3. The application deserializes the malicious data, instantiating attacker-controlled objects
4. These objects modify application logic during execution, leading to unintended behavior

The patch addresses this by implementing case-insensitive validation for phar file detection:

    $confFile = $values['configuration_file'];
    $uploadPath = $values['upload_path'];

-    $isPharFile = str_starts_with($confFile, 'phar://')
-        || str_starts_with($coursePath, 'phar://')
-        || str_starts_with($homePath, 'phar://')
-        || str_starts_with($uploadPath, 'phar://');
-
-    $isWritable = is_dir($coursePath)
-        && is_dir($homePath)
-        && is_dir($uploadPath)
-        && file_exists($confFile)
-        && is_readable($confFile);
-
-    if (!$isPharFile && $isWritable) {
-        $currentHost = api_get_configuration_value('db_host');
-        $currentDatabase = api_get_configuration_value('main_database');
-        $currentUser = api_get_configuration_value('db_user');
-        $currentPassword = api_get_configuration_value('db_password');
-
-        if ($values['to_main_database'] !== $currentDatabase &&
-            $values['to_db_user'] !== $currentUser &&
-            $values['to_db_password'] !== $currentPassword
-        ) {
-        } else {
-            Display::addFlash(
-                Display::return_message(
-                    $plugin->get_lang('DatabaseAccessShouldBeDifferentThanMasterChamilo'),
-                    'warning'
-                )

Source: GitHub Commit ba7e15d8cfefcd451de939e98d461b17e72eb627

Detection Methods for CVE-2025-52998

Indicators of Compromise

• Unusual HTTP requests to the VChamilo plugin import endpoint (/plugin/vchamilo/views/import.php)
• Request payloads containing serialized PHP objects or phar:// wrapper variations (case-insensitive)
• Error logs indicating unexpected object instantiation or class not found exceptions
• Abnormal application behavior or configuration changes without administrator action

Detection Strategies

• Monitor web server access logs for requests to the VChamilo plugin import functionality with suspicious parameters
• Implement web application firewall (WAF) rules to detect serialized PHP object patterns in request bodies
• Enable verbose application logging to capture deserialization events and unexpected class instantiations
• Deploy file integrity monitoring on Chamilo configuration and plugin directories

Monitoring Recommendations

• Configure SIEM alerts for anomalous access patterns to the VChamilo administrative endpoints
• Establish baseline behavior for privileged user actions and alert on deviations
• Monitor PHP error logs for deserialization-related warnings or errors
• Track file system changes within the Chamilo installation directory

How to Mitigate CVE-2025-52998

Immediate Actions Required

• Upgrade Chamilo LMS to version 1.11.30 or later immediately
• Review access logs for any suspicious activity targeting the VChamilo plugin import functionality
• Audit privileged user accounts for unauthorized access or compromised credentials
• Consider temporarily disabling the VChamilo plugin if upgrade cannot be performed immediately

Patch Information

Chamilo has released version 1.11.30 which addresses this vulnerability. The patch implements case-insensitive validation for phar file detection and strengthens the deserialization handling within the VChamilo plugin import functionality.

• GitHub Release v1.11.30
• GitHub Security Advisory GHSA-6mwg-2mw5-rx5v
• GitHub Commit ba7e15d8cfefcd451de939e98d461b17e72eb627

Workarounds

• Restrict access to the VChamilo plugin administrative interface to trusted IP addresses only
• Disable the VChamilo plugin entirely if multi-portal functionality is not required
• Implement web application firewall rules to block requests containing serialized PHP objects or phar:// wrappers
• Enforce strong authentication and limit privileged account access

# Example: Restrict access to VChamilo plugin in Apache configuration
<Directory "/var/www/chamilo/plugin/vchamilo">
    Order Deny,Allow
    Deny from all
    Allow from 10.0.0.0/8
    Allow from 192.168.0.0/16
</Directory>