CVE-2011-2511 in libvirt
Summary
by MITRE
Integer overflow in libvirt before 0.9.3 allows remote authenticated users to cause a denial of service (libvirtd crash) and possibly execute arbitrary code via a crafted VirDomainGetVcpus RPC call that triggers memory corruption.
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Analysis
by VulDB Data Team • 01/12/2025
The vulnerability identified as CVE-2011-2511 represents a critical integer overflow flaw within the libvirt virtualization management library version 0.9.2 and earlier. This vulnerability specifically affects the libvirtd daemon which serves as the central management service for virtualization environments. The flaw exists in the handling of the VirDomainGetVcpus Remote Procedure Call mechanism, which is used to retrieve virtual CPU information from virtual machines. The integer overflow occurs when processing crafted input parameters within the RPC call structure, creating a scenario where the application fails to properly validate input sizes before performing memory allocation operations. This vulnerability demonstrates a classic software security weakness that can lead to both denial of service conditions and potential code execution capabilities.
The technical implementation of this vulnerability stems from improper input validation within the libvirt daemon's RPC processing layer. When a remote authenticated user sends a specially crafted VirDomainGetVcpus RPC call, the application fails to properly check the size parameters provided in the request. This allows an attacker to manipulate the integer values in such a way that arithmetic overflow occurs during memory allocation calculations. The overflow results in the allocation of insufficient memory or incorrect memory regions, leading to memory corruption that can cause the libvirtd process to crash or potentially allow for arbitrary code execution. This type of vulnerability aligns with CWE-190, which specifically addresses integer overflow conditions, and demonstrates how improper integer handling can lead to memory safety issues.
The operational impact of CVE-2011-2511 extends beyond simple service disruption to potentially enable remote code execution within virtualization management environments. Attackers who can authenticate to the libvirt management interface can leverage this vulnerability to crash the libvirtd daemon, effectively denying service to all virtualization management operations. More critically, the memory corruption aspect suggests that under certain conditions, attackers might be able to manipulate the execution flow of the daemon to execute arbitrary code with the privileges of the libvirtd process. This creates a significant threat to virtualization infrastructure security, as the libvirtd daemon typically runs with elevated privileges and manages critical virtual machine operations. The vulnerability affects systems using libvirt versions prior to 0.9.3, making it a substantial concern for organizations maintaining older virtualization management configurations.
Mitigation strategies for CVE-2011-2511 primarily focus on upgrading to libvirt version 0.9.3 or later, where the integer overflow has been addressed through proper input validation and memory allocation checks. Organizations should implement immediate patch management procedures to update all affected libvirt installations and ensure that the libvirtd daemon is running with the latest security fixes. Network segmentation and access controls should be enforced to limit authentication access to the libvirt management interface, reducing the attack surface available to potential adversaries. Additionally, monitoring systems should be configured to detect unusual RPC call patterns or memory allocation behaviors that might indicate exploitation attempts. Security teams should consider implementing intrusion detection systems that can identify malformed RPC requests targeting the VirDomainGetVcpus functionality, and conduct regular vulnerability assessments to identify other potential integer overflow conditions within the virtualization management stack. The vulnerability also highlights the importance of proper input validation and memory safety practices in security-critical systems, aligning with ATT&CK technique T1059.007 for execution through remote services and T1499.004 for network denial of service attacks.