CVE-2006-1174 in shadow
Summary
by MITRE
useradd in shadow-utils before 4.0.3, and possibly other versions before 4.0.8, does not provide a required argument to the open function when creating a new user mailbox, which causes the mailbox to be created with unpredictable permissions and possibly allows attackers to read or modify the mailbox.
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Analysis
by VulDB Data Team • 01/20/2025
The vulnerability identified as CVE-2006-1174 affects the useradd utility within shadow-utils package versions prior to 4.0.3 and potentially earlier versions before 4.0.8. This represents a critical security flaw in user account management functionality that impacts Unix-like operating systems. The issue stems from improper argument handling within the mailbox creation process, specifically when the open function is invoked during user mailbox initialization. The flaw manifests when the useradd command fails to provide a required argument to the open system call, leading to unpredictable file permissions for newly created user mailboxes.
The technical implementation of this vulnerability involves the useradd utility's interaction with the open system call during mailbox creation. When creating a new user account, the system should properly specify file creation flags and permissions to ensure mailbox security. However, due to the missing argument, the open function operates with default or unpredictable parameters, allowing for insecure file creation. This misconfiguration enables attackers to potentially access or manipulate mailbox contents through various attack vectors including privilege escalation or information disclosure. The vulnerability directly relates to CWE-276, which addresses incorrect permissions for created files, and CWE-732, which covers incorrect permissions for security-critical resources.
The operational impact of this vulnerability extends across multiple security domains and attack surfaces. An attacker with access to the system or even limited privileges could exploit this flaw to gain unauthorized access to user mailboxes, potentially reading sensitive email communications or modifying mailbox contents. This could lead to information leakage, data tampering, or serve as a foothold for further system compromise. The vulnerability particularly affects systems where user account management is frequently performed, and where mailbox security is paramount for maintaining confidentiality and integrity of user communications. The impact is amplified when considering that mailbox files often contain sensitive personal or business information, making this a significant concern for enterprise environments and security-conscious organizations.
Mitigation strategies for CVE-2006-1174 involve immediate patching of shadow-utils to versions 4.0.3 or later, which properly address the argument passing issue to the open function. System administrators should also implement monitoring for unauthorized user account creation activities and verify mailbox permissions regularly. Additional security controls include implementing proper access controls, ensuring that mailbox directories have appropriate permissions, and conducting regular security audits of user account management processes. Organizations should also consider implementing automated patch management systems to ensure timely deployment of security updates. The vulnerability demonstrates the importance of proper input validation and argument handling in system utilities, aligning with ATT&CK technique T1068 which covers privilege escalation through exploitation of system vulnerabilities. Regular security assessments and adherence to security best practices regarding file permissions and access controls remain essential defensive measures against similar vulnerabilities in system utilities.