CVE-2012-3394 in Moodle
Summary
by MITRE
auth/ldap/ntlmsso_attempt.php in Moodle 2.0.x before 2.0.10, 2.1.x before 2.1.7, 2.2.x before 2.2.4, and 2.3.x before 2.3.1 redirects users from an https LDAP login URL to an http URL, which allows remote attackers to obtain sensitive information by sniffing the network.
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Analysis
by VulDB Data Team • 12/06/2021
The vulnerability identified as CVE-2012-3394 affects Moodle authentication systems and represents a critical security flaw in the handling of secure authentication redirects. This issue exists within the auth/ldap/ntlmsso_attempt.php file across multiple Moodle versions, specifically impacting releases before 2.0.10, 2.1.7, 2.2.4, and 2.3.1. The flaw manifests when users attempt to authenticate through LDAP or NTLM Single Sign-On mechanisms, creating a dangerous transition from secure to insecure network communication that exposes sensitive user credentials and authentication data to potential interception.
The technical implementation of this vulnerability stems from improper URL handling within the authentication flow where the system automatically redirects users from a secure https connection to an unencrypted http connection. This redirect occurs specifically during the LDAP authentication process, where the system fails to maintain the security context established during the initial secure login attempt. The flaw creates a man-in-the-middle attack vector that allows remote adversaries to capture authentication tokens, usernames, and passwords through network packet sniffing operations, effectively undermining the security assurances provided by HTTPS encryption.
The operational impact of this vulnerability extends beyond simple credential theft, as it fundamentally compromises the integrity of the authentication system itself. Attackers can exploit this weakness to perform session hijacking, gain unauthorized access to user accounts, and potentially escalate privileges within the Moodle environment. The vulnerability affects all users attempting LDAP or NTLM authentication, making it particularly dangerous for organizations relying on these authentication methods. This flaw directly violates security best practices outlined in the OWASP Top Ten and represents a clear violation of the principle of least privilege, as users' credentials are exposed to network-level attacks.
Organizations affected by this vulnerability should immediately implement mitigations including upgrading to patched Moodle versions, implementing strict redirect policies that prevent insecure protocol transitions, and configuring network firewalls to block insecure HTTP traffic. The mitigation strategy should also include network monitoring to detect and prevent unauthorized protocol switching, as well as implementing additional authentication layers such as multi-factor authentication to reduce the impact of credential compromise. This vulnerability aligns with ATT&CK technique T1566 for credential access through network sniffing and represents a clear violation of security controls specified in NIST SP 800-53 and ISO 27001 standards. The flaw demonstrates the critical importance of maintaining secure communication channels throughout authentication processes and highlights the necessity of comprehensive security testing that includes protocol transition validation.