CVE-2013-0241 in Enterprise Linux Workstation
Summary
by MITRE
The QXL display driver in QXL Virtual GPU 0.1.0 allows local users to cause a denial of service (guest crash or hang) via a SPICE connection that prevents other threads from obtaining the qemu_mutex mutex. NOTE: some of these details are obtained from third party information.
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Analysis
by VulDB Data Team • 12/28/2024
The vulnerability identified as CVE-2013-0241 resides within the QXL display driver component of QXL Virtual GPU version 0.1.0, which is part of the SPICE (Simple Protocol for Independent Computing Environments) ecosystem used for remote desktop virtualization. This flaw specifically affects the synchronization mechanisms employed by the virtual graphics driver when handling concurrent operations through SPICE connections. The QXL driver serves as a critical interface between the virtual machine's graphics processing and the host system's display capabilities, making it a prime target for exploitation that could compromise the stability of virtualized environments. The vulnerability manifests when local users establish SPICE connections to virtual machines running this particular driver version, creating conditions that can lead to system-wide operational failures.
The technical root cause of this vulnerability lies in improper mutex handling within the qemu_mutex synchronization primitive used by the QXL driver. When a SPICE connection is established, the driver attempts to acquire a qemu_mutex lock to coordinate access to shared resources and maintain thread safety during graphics processing operations. However, the implementation contains a flaw that allows malicious or malformed SPICE connection sequences to cause the mutex acquisition to block indefinitely or inappropriately, preventing other threads from accessing critical graphics processing resources. This mutex starvation condition effectively creates a deadlock scenario where the virtual machine's graphics subsystem becomes unresponsive, leading to guest crashes or system hangs that severely impact the usability of the virtualized environment.
The operational impact of this vulnerability extends beyond simple denial of service, as it can disrupt critical virtualized workloads and compromise the reliability of enterprise virtualization platforms. When the QXL driver becomes unresponsive due to mutex contention issues, it affects not only the graphics capabilities of the virtual machine but can also cause cascading failures in other system components that depend on proper graphics handling. The vulnerability is particularly concerning in environments where virtual machines are running critical applications or services, as the resulting system hangs or crashes can lead to significant downtime and data loss. From an attacker perspective, this vulnerability represents a low-effort method to disrupt virtualized environments, making it attractive for malicious actors seeking to compromise system availability in cloud computing or virtual desktop infrastructure deployments.
Mitigation strategies for CVE-2013-0241 should focus on immediate version upgrades to patched releases of QXL Virtual GPU that address the mutex handling issues. Organizations should implement comprehensive patch management procedures to ensure all virtualization components are updated promptly, as this vulnerability affects the core graphics driver functionality that is fundamental to virtual desktop environments. The flaw aligns with CWE-362, which describes "Concurrent Execution using Shared Resource with Unprotected Read-Write Access," and represents a classic race condition scenario where improper synchronization leads to system instability. From an ATT&CK framework perspective, this vulnerability could be categorized under T1499.004 for "Endpoint Denial of Service" as it specifically targets the availability of virtual machine endpoints through graphics driver manipulation. Additionally, organizations should consider implementing monitoring solutions that can detect unusual SPICE connection patterns or mutex contention issues that may indicate exploitation attempts, while also maintaining robust backup and recovery procedures to minimize the impact of potential service disruptions caused by this vulnerability.