CVE-2013-2218 in libvirt
Summary
by MITRE
Double free vulnerability in the virConnectListAllInterfaces method in interface/interface_backend_netcf.c in libvirt 1.0.6 allows remote attackers to cause a denial of service (libvirtd crash) via a filtering flag that causes an interface to be skipped, as demonstrated by the "virsh iface-list --inactive" command.
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Analysis
by VulDB Data Team • 11/24/2024
The vulnerability identified as CVE-2013-2218 represents a critical double free condition within the libvirt virtualization management library, specifically affecting version 1.0.6. This flaw exists in the interface_backend_netcf.c file within the virConnectListAllInterfaces method, creating a scenario where memory management becomes corrupted due to improper handling of interface enumeration operations. The vulnerability manifests when remote attackers exploit a filtering mechanism that causes certain interfaces to be skipped during enumeration, leading to a cascade of memory deallocation errors that ultimately result in libvirtd daemon crashes.
The technical implementation of this vulnerability stems from inadequate memory management practices during the processing of interface lists in libvirt's network configuration backend. When the virsh command with the --inactive flag executes, it triggers the problematic code path where the filtering flag causes interfaces to be skipped, but the memory allocation and deallocation sequences are not properly synchronized. This results in the same memory block being freed twice, a classic double free vulnerability pattern that violates fundamental memory safety principles. The vulnerability operates at the intersection of memory corruption and resource management, where the expected single allocation is followed by multiple deallocations, creating a state where the heap management structures become corrupted and the application terminates abnormally.
The operational impact of this vulnerability extends beyond simple service disruption to potentially enable more sophisticated attack vectors within virtualized environments. When libvirtd crashes due to this double free condition, it creates a denial of service scenario that can affect the entire virtualization infrastructure managed by libvirt, potentially disrupting multiple virtual machines and their associated services. The remote nature of the attack means that unauthorized users can exploit this vulnerability from external networks without requiring local system access, making it particularly dangerous in cloud and enterprise virtualization deployments. This vulnerability affects the core management capabilities of libvirt, which serves as the primary interface for managing virtual machines across numerous Linux distributions and cloud platforms.
Mitigation strategies for CVE-2013-2218 should prioritize immediate patch application to libvirt version 1.0.7 or later, which contains the necessary memory management fixes. System administrators should implement network segmentation and access controls to limit exposure of libvirt management interfaces to trusted networks only, while also monitoring for unusual patterns in libvirtd process behavior that might indicate exploitation attempts. The vulnerability aligns with CWE-415, which describes improper handling of memory allocation and deallocation sequences, and can be mapped to ATT&CK technique T1499.001 for denial of service attacks targeting system services. Organizations should also consider implementing intrusion detection systems that can monitor for exploitation patterns and maintain regular backup and recovery procedures to minimize downtime during potential exploitation events.