CVE-2013-4367 in ovirt-engine
Summary
by MITRE
ovirt-engine 3.2 running on Linux kernel 3.1 and newer creates certain files world-writeable due to an upstream kernel change which impacted how python's os.chmod() works when passed a mode of '-1'.
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Analysis
by VulDB Data Team • 02/01/2024
The vulnerability identified as CVE-2013-4367 represents a critical security flaw in the ovirt-engine 3.2 platform that operates on Linux kernel versions 3.1 and later. This issue stems from a fundamental change in kernel behavior that directly impacts how the Python operating system module handles file permission modifications. The root cause lies in the upstream kernel modification that altered the interpretation of the os.chmod() function when invoked with a mode parameter set to '-1', creating a scenario where certain critical files are inadvertently created with world-writeable permissions.
The technical implementation of this vulnerability occurs through the interaction between the ovirt-engine's file creation processes and the modified kernel behavior. When the engine attempts to set file permissions using Python's os.chmod() function with a mode of '-1', the newer kernel versions interpret this parameter differently than expected by the application code. This misinterpretation results in files being created with overly permissive permissions, specifically allowing write access to all users on the system. The flaw essentially bypasses normal permission controls that should restrict file access to authorized users only.
The operational impact of this vulnerability is severe and far-reaching within virtualization environments managed by ovirt-engine. Attackers who gain access to the system can exploit these world-writeable files to modify critical configuration data, inject malicious code, or escalate privileges within the virtualization infrastructure. The vulnerability affects the integrity and confidentiality of the entire virtualization platform, potentially allowing unauthorized users to compromise the underlying virtual machines and the data they contain. This represents a direct violation of the principle of least privilege that should govern file access controls in enterprise environments.
This vulnerability aligns with CWE-732, which specifically addresses inadequate permissions for critical resources, and falls under the ATT&CK technique T1059 for execution through command and scripting interpreter. The flaw demonstrates how kernel-level changes can cascade through application layers, creating unexpected security implications that may not be immediately apparent to developers or security teams. Organizations using ovirt-engine 3.2 should prioritize immediate patching and remediation efforts, as the vulnerability creates persistent access vectors that can be exploited by both internal and external threat actors. The recommended mitigation strategy involves updating to patched versions of ovirt-engine that properly handle the kernel's modified behavior or implementing additional access controls to prevent unauthorized modification of critical system files.
The broader implications of this vulnerability highlight the importance of thorough testing when kernel updates are deployed, particularly in enterprise environments where application compatibility and security assumptions are paramount. System administrators must carefully evaluate the impact of kernel changes on all applications that rely on specific permission behaviors, as seemingly minor modifications can create significant security risks. This case underscores the necessity of maintaining comprehensive security testing procedures that account for both application-level and kernel-level interactions to prevent such cascading security issues from affecting production environments.