CVE-2018-11749 in Puppet Enterprise
Summary
by MITRE
When users are configured to use startTLS with RBAC LDAP, at login time, the user's credentials are sent via plaintext to the LDAP server. This affects Puppet Enterprise 2018.1.3, 2017.3.9, and 2016.4.14, and is fixed in Puppet Enterprise 2018.1.4, 2017.3.10, and 2016.4.15. It scored an 8.5 CVSS score.
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Analysis
by VulDB Data Team • 03/18/2020
This vulnerability represents a critical security flaw in Puppet Enterprise's LDAP authentication implementation where plaintext credential transmission occurs despite configured startTLS encryption. The issue specifically impacts environments using Role-Based Access Control with Lightweight Directory Access Protocol authentication, creating a significant attack surface that allows adversaries to intercept sensitive user credentials during the login process. The vulnerability exists because the system fails to properly enforce TLS encryption during the initial authentication handshake, leaving user credentials exposed to network interception attacks.
The technical flaw stems from improper handling of the LDAP connection lifecycle where the system establishes an initial plaintext connection before transitioning to TLS encryption. This timing issue creates a window of opportunity for man-in-the-middle attacks, where malicious actors can capture credentials as they traverse the network. The vulnerability is categorized under CWE-310 as "Cryptographic Issues" and specifically relates to improper implementation of TLS/SSL protocols in authentication contexts. From an attack perspective, this aligns with ATT&CK technique T1075 which covers legitimate credentials used for lateral movement, as compromised credentials can then be used to access additional systems within the enterprise environment.
The operational impact of this vulnerability extends beyond simple credential theft, as it enables attackers to gain unauthorized access to Puppet Enterprise management capabilities and potentially escalate privileges within the infrastructure. The CVSS score of 8.5 indicates high severity with a base score reflecting the ease of exploitation and significant impact on system security. Organizations using affected Puppet Enterprise versions face risks of unauthorized access to configuration management systems, which could lead to complete infrastructure compromise. The vulnerability affects multiple major releases, suggesting a systemic issue in the LDAP authentication module implementation.
Mitigation strategies should focus on immediate patch deployment to the fixed versions of Puppet Enterprise, ensuring all affected systems are updated to prevent credential interception. Network-level protections including intrusion detection systems and monitoring for unusual LDAP traffic patterns should be implemented to detect potential exploitation attempts. Organizations should also consider implementing additional authentication layers such as two-factor authentication to reduce the impact of credential compromise. The vulnerability highlights the importance of proper TLS implementation in authentication flows and demonstrates the critical need for security testing of encryption protocols in enterprise management systems. Regular security audits of authentication mechanisms and network traffic monitoring are essential to prevent similar issues in other components of the infrastructure.