CVE-2020-1778 in OTRS
Summary
by MITRE • 11/23/2020
When OTRS uses multiple backends for user authentication (with LDAP), agents are able to login even if the account is set to invalid. This issue affects OTRS; 8.0.9 and prior versions.
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Analysis
by VulDB Data Team • 12/09/2020
The vulnerability described in CVE-2020-1778 represents a critical authentication bypass flaw within the OTRS (Open Ticket Request System) platform that specifically impacts versions 8.0.9 and earlier. This issue arises when the system is configured to utilize multiple authentication backends, particularly when LDAP (Lightweight Directory Access Protocol) is one of the configured methods. The fundamental problem occurs within the authentication validation process where the system fails to properly enforce account status checks across all configured authentication sources. When an agent's account is marked as invalid or disabled within one authentication backend, the system should prevent login attempts regardless of the backend used. However, this vulnerability allows authenticated users to bypass this critical security control, enabling unauthorized access through compromised or disabled accounts.
The technical root cause of this vulnerability stems from improper authentication flow handling within OTRS's multi-backend authentication system. According to CWE-287, this represents an authentication bypass weakness where the system fails to properly validate account status during the authentication process. The flaw manifests when the system processes authentication requests through multiple backends and does not adequately cross-reference account validity states between different authentication sources. This creates a scenario where even if one backend explicitly marks an account as invalid, the authentication system may still grant access if another backend successfully validates the credentials. The issue specifically affects environments where LDAP is configured as one of multiple authentication methods, making it particularly relevant for organizations that rely on centralized directory services for user management.
From an operational security perspective, this vulnerability presents a significant risk to organizations using OTRS for customer service management and ticket handling. The impact extends beyond simple unauthorized access to include potential data breaches, service disruption, and compliance violations. An attacker could exploit this vulnerability to gain access to sensitive customer information, manipulate support tickets, or conduct malicious activities within the system while appearing to be a legitimate agent. The vulnerability is particularly concerning because it undermines the principle of least privilege and account management controls that organizations rely on for security. According to ATT&CK framework category T1078, this vulnerability enables adversaries to gain access to valid accounts, which can then be used for persistence and privilege escalation within the environment. The risk is compounded in organizations that depend on LDAP for centralized user management, as the vulnerability effectively allows bypassing the directory service's account validation mechanisms.
Organizations should implement immediate mitigations to address this vulnerability by upgrading to OTRS version 8.0.10 or later, which contains the necessary patches to resolve the authentication bypass issue. Additionally, system administrators should review and enforce strict account management policies, ensuring that disabled accounts are properly synchronized across all authentication backends. The mitigation strategy should include regular audits of user accounts and authentication configurations to prevent unauthorized access. Security teams should also implement monitoring solutions that can detect anomalous login patterns or access attempts from disabled accounts, providing additional layers of defense. Organizations should consider implementing additional authentication controls such as multi-factor authentication and access logging to enhance overall security posture. The vulnerability highlights the importance of proper authentication flow validation and cross-backend account status verification, which should be integrated into security reviews and penetration testing procedures to prevent similar issues in other systems.