CVE-2012-5644 in libuser
Summary
by MITRE
libuser has information disclosure when moving user's home directory
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Analysis
by VulDB Data Team • 01/24/2026
The vulnerability identified as CVE-2012-5644 resides within the libuser library, a critical component responsible for user account management in Unix-like operating systems. This library handles various user-related operations including user creation, modification, and deletion processes. The flaw manifests specifically during the process of moving a user's home directory from one location to another, which is a routine administrative task performed when reorganizing system resources or migrating user data between storage devices. The libuser library operates with elevated privileges and interacts directly with the file system to manage user permissions and directory structures, making it a prime target for exploitation by malicious actors seeking unauthorized access to sensitive information.
The technical nature of this vulnerability stems from improper handling of file permissions and directory ownership during the home directory relocation process. When the libuser library executes the move operation, it fails to correctly validate or enforce proper access controls on the destination directory. This oversight creates a window where temporary files or directory structures may be created with insecure permissions, potentially exposing sensitive user data or system information. The flaw represents a classic case of insufficient privilege management and inadequate input validation, allowing for information disclosure that can reveal user account details, file permissions, or other system metadata that should remain restricted. The vulnerability can be exploited by local users or potentially remote attackers who can manipulate the directory move operation to gain access to information they should not normally be able to retrieve.
The operational impact of CVE-2012-5644 extends beyond simple information disclosure, as it can provide attackers with valuable reconnaissance data for subsequent attacks. The leaked information may include user account details, directory structures, file permissions, or other metadata that can be leveraged to craft more sophisticated attacks. This vulnerability particularly affects systems where libuser is actively used for user management, which includes many enterprise environments and server deployments. The information disclosure can be exploited to identify valid user accounts, understand system organization, or discover potential attack vectors within the file system hierarchy. Security professionals should note that this vulnerability can significantly weaken the overall security posture of affected systems, as the leaked information can be used to tailor more targeted attacks against specific users or system components.
Mitigation strategies for this vulnerability should focus on immediate patching of the libuser library to address the improper permission handling during directory relocation operations. System administrators should ensure that all affected systems receive updates from their respective vendors or distribution maintainers to resolve the information disclosure issue. Additionally, implementing proper access control measures and monitoring for unauthorized directory move operations can help detect potential exploitation attempts. The vulnerability aligns with CWE-200, which addresses "Information Exposure," and can be mapped to ATT&CK technique T1087.001 for account discovery and T1068 for local privilege escalation. Organizations should also consider implementing least privilege principles when managing user account operations and regularly audit directory permissions to prevent unauthorized access to sensitive information during routine system maintenance operations.