CVE-2012-3445 in libvirt
Summary
by MITRE
The virTypedParameterArrayClear function in libvirt 0.9.13 does not properly handle virDomain* API calls with typed parameters, which might allow remote authenticated users to cause a denial of service (libvirtd crash) via an RPC command with nparams set to zero, which triggers an out-of-bounds read or a free of an invalid pointer.
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Analysis
by VulDB Data Team • 12/31/2024
The vulnerability identified as CVE-2012-3445 resides within the libvirt virtualization management library version 0.9.13, specifically within the virTypedParameterArrayClear function. This flaw represents a critical security issue that affects the stability and reliability of virtualization environments managed through libvirt. The vulnerability manifests when the library processes RPC commands containing domain API calls with typed parameters, creating a scenario where legitimate authenticated users can exploit the system to cause unexpected behavior in the libvirtd daemon. The root cause stems from improper input validation and memory management within the parameter handling routines, particularly when dealing with edge cases involving parameter counts set to zero.
The technical implementation of this vulnerability involves a specific memory access pattern that occurs during the processing of domain API calls. When an RPC command is received with nparams set to zero, the virTypedParameterArrayClear function fails to properly validate this boundary condition, leading to either an out-of-bounds memory read operation or an attempt to free an invalid memory pointer. This improper handling creates a scenario where the libvirtd process can crash due to memory corruption, resulting in a denial of service condition that affects all virtual machines managed by the compromised daemon. The vulnerability is classified as a memory safety issue that aligns with CWE-125 for out-of-bounds read and CWE-416 for use-after-free conditions, both of which are fundamental memory management errors that can lead to system instability and potential privilege escalation.
From an operational impact perspective, this vulnerability presents a significant threat to virtualized environments as it allows authenticated attackers to disrupt services without requiring elevated privileges. The denial of service condition affects the entire libvirt management infrastructure, potentially causing widespread disruption across multiple virtual machines hosted on the affected system. The vulnerability is particularly concerning because it can be exploited through legitimate API calls, making it difficult to distinguish between malicious and benign usage patterns. Network-based exploitation becomes possible since the vulnerability exists within the RPC processing layer, allowing remote authenticated users to craft malicious commands that trigger the memory corruption. This issue directly impacts the availability and reliability of virtualization platforms, as demonstrated by the ATT&CK technique T1499.004 for network denial of service, which describes how attackers can disrupt services through protocol-level vulnerabilities.
The mitigation strategies for this vulnerability should focus on immediate patching of the libvirt library to version 0.9.14 or later, which contains the necessary fixes for the memory handling issues. System administrators should implement network segmentation and access controls to limit the number of authenticated users who can submit RPC commands to the libvirt daemon. Additionally, monitoring should be enhanced to detect unusual patterns in parameter counts and API call sequences that might indicate exploitation attempts. The vulnerability also highlights the importance of proper input validation and memory management in virtualization software, emphasizing the need for comprehensive testing of edge cases in API parameter handling. Organizations should conduct regular security assessments of their virtualization infrastructure and implement automated patch management processes to prevent similar vulnerabilities from persisting in their environments. The fix implemented in subsequent versions addresses the root cause by properly validating parameter counts and ensuring that memory operations are only performed on valid memory regions, thereby preventing the out-of-bounds access and invalid pointer free conditions that led to the crash.