CVE-2015-5224 in util-linux
Summary
by MITRE
The mkostemp function in login-utils in util-linux when used incorrectly allows remote attackers to cause file name collision and possibly other attacks.
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Analysis
by VulDB Data Team • 12/04/2025
The vulnerability identified as CVE-2015-5224 resides within the mkostemp function implementation in the login-utils component of util-linux, a critical set of system utilities that forms the foundation of many Linux distributions. This flaw represents a significant security weakness that can be exploited by remote attackers to manipulate file creation processes and potentially gain unauthorized access to system resources. The vulnerability specifically manifests when the mkostemp function is invoked with improper parameters or in scenarios where the temporary file creation mechanism is not properly secured against adversarial interference.
The technical root cause of this vulnerability stems from inadequate validation and handling of temporary file names within the mkostemp function. When this function is called incorrectly, it fails to properly randomize or secure the naming convention used for temporary files, creating predictable patterns that attackers can exploit to perform file name collision attacks. The flaw allows adversaries to anticipate and potentially pre-create temporary files with specific names, thereby enabling them to manipulate the execution flow or inject malicious content into files that should remain protected. This issue directly relates to CWE-377, which addresses insecure temporary file handling practices, and CWE-379, which covers the creation of temporary files and directories with insecure permissions.
The operational impact of CVE-2015-5224 extends beyond simple file manipulation as it can enable various attack vectors including privilege escalation, data corruption, and unauthorized system access. Remote attackers can leverage this vulnerability to overwrite critical system files, inject malicious code into temporary files that will be executed by legitimate system processes, or create symbolic links that redirect file operations to unintended destinations. The implications are particularly severe in multi-user environments where the temporary file creation mechanism is frequently utilized by system services and user applications. This vulnerability can be classified under the ATT&CK technique T1059 for command and scripting interpreter usage and T1078 for valid accounts, as it can facilitate unauthorized access and execution of malicious code through compromised temporary file mechanisms.
Mitigation strategies for CVE-2015-5224 require immediate patching of the affected util-linux package to ensure proper implementation of the mkostemp function with secure temporary file creation practices. System administrators should implement comprehensive monitoring of temporary file creation activities to detect anomalous patterns that may indicate exploitation attempts. The recommended approach includes verifying that all instances of mkostemp usage follow secure coding practices with proper randomization of file names and appropriate permission settings. Additionally, organizations should conduct thorough security assessments of their system utilities to identify similar vulnerabilities in other temporary file handling functions. Network segmentation and access controls should be enforced to limit potential attack surfaces, while regular security audits should verify that temporary file directories have appropriate permissions and are regularly cleaned to prevent accumulation of potentially vulnerable files. The vulnerability demonstrates the critical importance of secure temporary file handling practices as outlined in the OWASP Top Ten and other security frameworks that emphasize the need for proper input validation and secure resource management in system utilities.