CVE-2026-28430: Chamilo LMS SQL Injection Vulnerability

CVE-2026-28430 Overview

CVE-2026-28430 is a critical unauthenticated SQL injection vulnerability affecting Chamilo LMS, a widely-used open-source learning management system. The vulnerability exists in the custom_dates parameter and allows remote attackers to execute arbitrary SQL commands without requiring any prior authentication. When chained with a predictable legacy password reset mechanism, attackers can achieve full administrative account takeover, exposing the entire database including personally identifiable information (PII) and system configurations.

Critical Impact

This vulnerability enables complete database compromise and administrative account takeover without authentication, potentially exposing sensitive student data, credentials, and system configurations in educational environments.

Affected Products

• Chamilo LMS versions prior to 1.11.34
• All installations using the vulnerable custom_dates parameter endpoint
• Systems with the legacy password reset mechanism enabled

Discovery Timeline

• 2026-03-16 - CVE-2026-28430 published to NVD
• 2026-03-17 - Last updated in NVD database

Technical Details for CVE-2026-28430

Vulnerability Analysis

This SQL injection vulnerability (CWE-89) exists in Chamilo LMS prior to version 1.11.34. The vulnerability allows unauthenticated remote attackers to inject and execute arbitrary SQL commands through the custom_dates parameter. What makes this vulnerability particularly dangerous is the attack chain potential: an attacker can leverage the SQL injection to extract sensitive data and then exploit a predictable legacy password reset mechanism to achieve full administrative account takeover.

The attack requires no prior authentication or user interaction, making it trivial to exploit from a network perspective. Successful exploitation grants attackers access to the entire database contents, including user credentials, PII of students and instructors, course materials, and system configuration data.

Root Cause

The root cause of this vulnerability is improper input validation and sanitization of the custom_dates parameter. User-supplied input is directly incorporated into SQL queries without adequate parameterization or escaping, allowing attackers to manipulate the query structure and inject malicious SQL statements. This is compounded by the presence of a predictable legacy password reset mechanism that can be exploited once database access is obtained.

Attack Vector

The attack is network-based and requires no authentication or user interaction. An attacker can craft malicious HTTP requests containing SQL injection payloads in the custom_dates parameter. The exploitation flow typically involves:

1. Sending crafted requests with SQL injection payloads to the vulnerable endpoint
2. Extracting administrator email addresses and password reset tokens from the database
3. Leveraging the predictable legacy password reset mechanism to generate valid reset links
4. Resetting administrator passwords to gain full administrative access

Due to the sensitive nature of this vulnerability and the lack of verified proof-of-concept code, specific exploitation details are not provided. Security researchers and administrators should refer to the GitHub Security Advisory GHSA-84gw-qjw9-v8jv for technical details.

Detection Methods for CVE-2026-28430

Indicators of Compromise

• Unusual SQL error messages in web server logs or application logs
• Unexpected database queries containing UNION SELECT, information_schema, or other SQL injection signatures
• Multiple password reset requests for administrative accounts from unfamiliar IP addresses
• Evidence of database enumeration or bulk data extraction in access logs
• Suspicious requests targeting endpoints with the custom_dates parameter

Detection Strategies

• Deploy web application firewall (WAF) rules to detect and block SQL injection patterns in the custom_dates parameter
• Implement database activity monitoring to detect unusual query patterns or unauthorized data access
• Monitor authentication logs for suspicious password reset activity, particularly for privileged accounts
• Enable verbose logging on Chamilo LMS and correlate with network traffic analysis
• Utilize intrusion detection systems (IDS) with signatures for SQL injection attack patterns

Monitoring Recommendations

• Establish baseline normal traffic patterns to the vulnerable endpoint and alert on deviations
• Configure real-time alerting for SQL injection signatures in request parameters
• Monitor for unusual database read operations, especially targeting user tables and configuration data
• Track password reset request volumes and patterns for administrative accounts
• Implement log aggregation and SIEM correlation for comprehensive visibility

How to Mitigate CVE-2026-28430

Immediate Actions Required

• Upgrade Chamilo LMS to version 1.11.34 or later immediately
• If immediate patching is not possible, implement WAF rules to block malicious requests to the vulnerable endpoint
• Review database access logs for evidence of prior exploitation
• Audit administrative accounts and force password resets as a precautionary measure
• Consider temporarily disabling the legacy password reset mechanism if possible

Patch Information

The vulnerability has been patched in Chamilo LMS version 1.11.34. Administrators should upgrade to this version or later to remediate the vulnerability. The patch is available through the official GitHub release. Review the GitHub Security Advisory for complete details on the fix.

Workarounds

• Deploy a web application firewall with rules to block SQL injection patterns in the custom_dates parameter
• Implement network-level access controls to restrict access to the Chamilo LMS administrative interface
• Consider placing the application behind a reverse proxy with additional input validation
• Disable or restrict access to the legacy password reset functionality until patching is complete
• Implement database-level monitoring and alerting for suspicious query activity

# Example WAF rule for blocking SQL injection in custom_dates parameter
# ModSecurity rule example
SecRule ARGS:custom_dates "@detectSQLi" \
    "id:1001,\
    phase:2,\
    deny,\
    status:403,\
    log,\
    msg:'SQL Injection attempt blocked in custom_dates parameter - CVE-2026-28430'"