CVE-2018-17955 in yast2-multipath
Summary
by MITRE
In yast2-multipath before version 4.1.1 a static temporary filename allows local attackers to overwrite files on systems without symlink protection
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 08/01/2023
The vulnerability identified as CVE-2018-17955 affects the yast2-multipath package version 4.1.1 and earlier, representing a significant local privilege escalation risk within Linux system administration tools. This flaw resides in the multipath configuration utility that manages storage device multipathing, a critical component for enterprise storage management and high availability systems. The issue manifests through the use of predictable temporary filenames that are created with insufficient randomness, creating opportunities for malicious local users to manipulate system files through symlink attacks.
The technical implementation of this vulnerability stems from improper handling of temporary file creation within the yast2-multipath utility. When the application generates temporary files during its operation, it employs static naming conventions rather than utilizing secure temporary file generation mechanisms. This predictable naming scheme allows attackers to create symbolic links with the same names before the legitimate process creates the actual temporary files, enabling them to redirect file operations to arbitrary locations on the filesystem. The flaw specifically impacts systems where symlink protection mechanisms are not properly enforced, making the attack surface more extensive in environments lacking proper security controls.
From an operational impact perspective, this vulnerability represents a serious threat to system integrity and security posture within enterprise environments that rely on yast2-multipath for storage management. Attackers with local access can potentially overwrite critical system files, configuration data, or even executable components with malicious content, leading to privilege escalation, system compromise, or denial of service conditions. The vulnerability is particularly concerning because it targets administrative tools that are often run with elevated privileges, potentially allowing attackers to gain root access or modify core system components. This type of flaw directly violates security principles outlined in the CWE taxonomy under CWE-377, which addresses insecure temporary file handling practices, and aligns with ATT&CK techniques focusing on privilege escalation through local system manipulation.
The mitigation strategy for this vulnerability requires immediate patching of the yast2-multipath package to version 4.1.1 or later, which implements proper temporary file generation mechanisms with sufficient randomness and security controls. System administrators should also implement additional safeguards such as verifying symlink protection mechanisms are enabled, monitoring for unauthorized temporary file creation patterns, and ensuring proper file permissions and ownership are maintained on system administration tools. Organizations should conduct comprehensive vulnerability assessments to identify systems running affected versions and implement automated patch management processes to prevent similar issues from arising in the future. The fix addresses the underlying design flaw by ensuring that temporary files are created with unique, unpredictable names and proper security attributes that prevent symlink-based attacks from succeeding.