CVE-2016-1601 in Linux Enterprise
Summary
by MITRE
yast2-users before 3.1.47, as used in SUSE Linux Enterprise 12 SP1, does not properly set empty password fields in /etc/shadow during an AutoYaST installation when the profile does not contain inst-sys users, which might allow attackers to have unspecified impact via unknown vectors.
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Analysis
by VulDB Data Team • 10/14/2024
The vulnerability identified as CVE-2016-1601 affects the yast2-users component in SUSE Linux Enterprise 12 SP1, specifically during AutoYaST installations where user profiles are configured automatically. This flaw resides in the system's handling of password fields within the /etc/shadow file, which serves as a critical security component storing user password information and account status details. The issue manifests when AutoYaST processes installation profiles that do not explicitly define inst-sys users, creating a scenario where empty password fields are not properly initialized or validated during the automated setup process. The vulnerability represents a significant security weakness as it could potentially allow unauthorized access to systems through unspecified attack vectors that leverage the improper handling of authentication credentials.
The technical root cause of this vulnerability stems from inadequate input validation and field initialization within the yast2-users module during automated installation workflows. When the AutoYaST profile lacks explicit user definitions for inst-sys users, the system fails to properly manage the password field entries in /etc/shadow, potentially leaving accounts with empty password hashes or improperly configured authentication states. This flaw directly relates to CWE-254, which addresses security weaknesses in the handling of authentication credentials, and more specifically to CWE-798, which deals with the use of hard-coded credentials. The improper configuration of password fields in shadow files creates potential attack surfaces where malicious actors could exploit the absence of proper password enforcement mechanisms to gain unauthorized system access.
The operational impact of CVE-2016-1601 extends beyond simple credential management issues, as it fundamentally undermines the authentication security model of affected SUSE Linux Enterprise systems. Systems deployed with vulnerable versions of yast2-users may exhibit unexpected behavior where user accounts are left in insecure states, potentially allowing for privilege escalation attacks or unauthorized logins. Attackers could exploit this vulnerability through various methods including social engineering to manipulate AutoYaST profiles or by directly manipulating system files to bypass authentication mechanisms. The unspecified impact vector suggests that the vulnerability could be leveraged in multiple attack scenarios, potentially including local privilege escalation or remote access exploitation depending on the system configuration and additional security controls in place. This weakness aligns with ATT&CK technique T1078 which covers valid accounts and privilege escalation through compromised authentication mechanisms.
Mitigation strategies for CVE-2016-1601 require immediate patching of affected systems to version 3.1.47 or later of yast2-users, which properly handles empty password field initialization during AutoYaST installations. Organizations should conduct comprehensive inventory assessments to identify all systems running vulnerable versions of SUSE Linux Enterprise 12 SP1 and ensure proper update deployment across their infrastructure. Security administrators should implement additional monitoring of /etc/shadow file modifications and conduct regular audits to detect any anomalous authentication state changes. System hardening practices should include mandatory password requirements for all user accounts and implementation of proper access controls for critical system files. The remediation process should also involve reviewing and updating AutoYaST profiles to explicitly define user accounts and their authentication requirements, eliminating the conditions that trigger the vulnerability. Organizations should consider implementing automated patch management solutions to prevent similar vulnerabilities from affecting their systems in the future, as this flaw demonstrates the importance of proper credential handling during automated system provisioning processes.