CVE-2008-4580 in cman
Summary
by MITRE
fence_manual, as used in fence 2.02.00-r1 and possibly cman, allows local users to modify arbitrary files via a symlink attack on the fence_manual.fifo temporary file.
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Analysis
by VulDB Data Team • 05/25/2025
The vulnerability described in CVE-2008-4580 represents a critical security flaw in the fence_manual component of the fence 2.02.00-r1 software package, which is part of the cluster management infrastructure commonly used in high-availability systems. This issue specifically affects the handling of temporary files during the execution of fencing operations, which are essential for maintaining system integrity in clustered environments where multiple nodes must coordinate their operations to prevent data corruption and ensure consistent service delivery.
The technical flaw stems from a race condition vulnerability in how fence_manual manages its temporary file named fence_manual.fifo. When the fence component executes, it creates this temporary file to facilitate communication between processes, but fails to properly validate or secure the file path before using it. Local users can exploit this by creating a symbolic link with the same name as the temporary file in a location where the fence process will attempt to access it, effectively redirecting the process to write to any arbitrary file on the system. This type of attack falls under the category of symlink-based attacks and specifically aligns with CWE-377, which addresses insecure temporary file creation vulnerabilities. The attack vector is particularly dangerous because it leverages the trust relationship between the fence component and its temporary file handling mechanism, allowing privilege escalation from a local user to a potentially more privileged system context.
The operational impact of this vulnerability extends beyond simple file modification capabilities and represents a serious threat to cluster integrity and system security. In high-availability environments where fence components are responsible for managing node fencing operations, an attacker who successfully exploits this vulnerability could potentially compromise the entire cluster infrastructure. The ability to modify arbitrary files means that attackers could corrupt critical system files, inject malicious code into the fencing process, or manipulate the cluster's operational state to cause denial of service or unauthorized access to protected resources. This vulnerability directly impacts the integrity and availability of cluster management systems and can be leveraged as a stepping stone for more sophisticated attacks within the cluster environment, aligning with ATT&CK technique T1059 for executing malicious code through system processes and T1499 for compromising availability through file system manipulation.
The recommended mitigations for this vulnerability involve immediate patching of the fence component to properly handle temporary file creation using secure methods such as creating files with restrictive permissions and using atomic operations to prevent symlink attacks. System administrators should implement proper file system permissions and access controls to limit the ability of local users to create symbolic links in directories where critical processes might create temporary files. Additionally, the software should be updated to use secure temporary file creation patterns that prevent race conditions, such as using the mkstemp() function or similar secure alternatives that guarantee unique file creation. Organizations should also consider implementing monitoring and alerting for unusual file system modifications in critical directories and conduct regular security assessments of cluster management components to identify and remediate similar vulnerabilities. The fix should also include proper input validation and sanitization of file paths to ensure that symbolic links are not followed when accessing temporary files, thereby preventing the exploitation of this race condition vulnerability that affects the core security model of the fencing infrastructure.