CVE-2011-0002 in libuser
Summary
by MITRE
libuser before 0.57 uses a cleartext password value of (1) !! or (2) x for new LDAP user accounts, which makes it easier for remote attackers to obtain access by specifying one of these values.
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Analysis
by VulDB Data Team • 12/01/2024
The vulnerability described in CVE-2011-0002 affects the libuser library version 0.57 and earlier, which is a critical component in Unix-like operating systems responsible for managing user accounts and authentication data. This flaw specifically impacts how new LDAP user accounts are initialized within the system's user management framework. The vulnerability stems from the library's improper handling of password initialization values during user account creation processes, creating a significant security weakness that can be exploited by remote attackers.
The technical flaw manifests when the libuser library creates new LDAP user accounts using predetermined cleartext password values of either "!!" or "x" as default passwords. This behavior represents a fundamental failure in secure password handling practices and violates multiple security principles outlined in the CWE (Common Weakness Enumeration) catalog. The weakness falls under CWE-256, which addresses "Plaintext Storage of a Password," and CWE-320, which covers "Use of Hard-coded Cryptographic Key." These hardcoded cleartext values create predictable authentication vectors that significantly weaken the overall security posture of systems relying on this library.
The operational impact of this vulnerability is substantial, as it provides remote attackers with a straightforward method to gain unauthorized access to user accounts. Attackers can exploit this weakness by simply specifying one of the two predetermined password values during account creation or authentication attempts. This vulnerability directly maps to techniques described in the MITRE ATT&CK framework under T1110, which covers "Brute Force" and "Credential Access" tactics. The predictable nature of these default passwords means that attackers can systematically attempt to authenticate using these known values, effectively bypassing normal authentication mechanisms and gaining unauthorized access to user accounts.
Systems utilizing libuser versions prior to 0.57 are particularly vulnerable to this attack vector, as the flaw exists in the core user management functionality that handles LDAP account provisioning. The vulnerability becomes more dangerous in environments where LDAP is used for centralized user authentication, as successful exploitation could lead to privilege escalation, lateral movement, and broader system compromise. Organizations should prioritize immediate remediation by upgrading to libuser version 0.57 or later, which addresses this specific weakness in password initialization. Additionally, security administrators should conduct comprehensive audits of all LDAP user accounts to identify and reset any accounts that may have been compromised through this vulnerability, ensuring that no unauthorized access has occurred through the use of these predictable default passwords.