CVE-2008-0931 in XWine
Summary
by MITRE
w_export.c in XWine 1.0.1 on Debian GNU/Linux sets insecure permissions (0666) for /etc/wine/config, which might allow local users to execute arbitrary commands or cause a denial of service by modifying the file.
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Analysis
by VulDB Data Team • 08/07/2019
The vulnerability identified as CVE-2008-0931 affects XWine 1.0.1 running on Debian GNU/Linux systems, specifically targeting the file permission configuration in the w_export.c component. This issue represents a critical security flaw that undermines the integrity and confidentiality of the system's wine configuration file. The vulnerability stems from the improper assignment of file permissions during the creation of /etc/wine/config, where the system sets permissions to 0666, granting read and write access to all users on the system. This configuration creates an exploitable condition that allows local attackers to manipulate the wine configuration file in ways that could compromise system security.
The technical flaw manifests through the insecure file permission model that fails to implement proper access controls for system-critical configuration files. The 0666 permission setting provides universal read and write capabilities, which violates fundamental security principles of least privilege and access control. When a local user can modify the wine configuration file, they gain the ability to inject malicious content that could be executed during wine application launches. This vulnerability directly maps to CWE-732, which describes improper permission assignment for critical system resources, and represents a classic case of inadequate file system access control implementation. The flaw enables privilege escalation scenarios where unprivileged users can potentially elevate their system privileges through manipulation of the wine configuration environment.
The operational impact of this vulnerability extends beyond simple denial of service to encompass potential system compromise and unauthorized command execution. Local users who exploit this vulnerability can modify the wine configuration file to include malicious commands or scripts that execute with the privileges of the wine process. This creates a vector for arbitrary code execution that could allow attackers to establish persistent access, escalate privileges, or perform other malicious activities within the compromised system. The vulnerability affects the integrity of the system's application compatibility layer and could potentially be leveraged in broader attack chains where attackers seek to establish footholds on target systems. The denial of service aspect occurs when malicious modifications cause wine applications to fail or behave unpredictably, disrupting legitimate system operations.
Mitigation strategies for CVE-2008-0931 should prioritize immediate permission correction to restrict access to the /etc/wine/config file. System administrators should implement proper file permissions that limit write access to authorized users or system processes only, typically using 0644 or more restrictive settings. The recommended approach involves setting permissions to 0644 for configuration files, ensuring only the owner can modify them while allowing read access to others. Additionally, implementing proper file system monitoring and integrity checking mechanisms can help detect unauthorized modifications to critical system files. Regular security audits should verify that configuration files maintain appropriate access controls and that no insecure permissions are inadvertently set during system updates or installations. This vulnerability demonstrates the importance of adhering to security best practices such as those outlined in the ATT&CK framework, particularly in the privilege escalation and persistence domains where improper file permissions can enable attackers to establish long-term system access.