CVE-2018-1064 in libvirt
Summary
by MITRE
libvirt version before 4.2.0-rc1 is vulnerable to a resource exhaustion as a result of an incomplete fix for CVE-2018-5748 that affects QEMU monitor but now also triggered via QEMU guest agent.
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Analysis
by VulDB Data Team • 02/24/2023
The vulnerability described in CVE-2018-1064 represents a significant resource exhaustion issue within the libvirt virtualization management library. This flaw affects versions prior to 4.2.0-rc1 and demonstrates the complex nature of security patches where remediation efforts can inadvertently create new attack surfaces. The vulnerability stems from an incomplete fix for CVE-2018-5748, which initially targeted QEMU monitor interfaces but has since been extended to encompass QEMU guest agent communications. This evolution illustrates how security researchers must continuously monitor and validate their fixes, as the interconnected nature of virtualization components can allow vulnerabilities to manifest in unexpected pathways.
The technical implementation of this vulnerability involves resource exhaustion mechanisms that occur when libvirt processes certain malformed or malicious inputs through the QEMU guest agent interface. This represents a classic denial of service scenario where an attacker can consume system resources such as memory or CPU cycles to the point where legitimate operations become impossible. The QEMU guest agent serves as a communication channel between the guest operating system and the hypervisor, making it a critical component for system management and monitoring functions. When this interface becomes vulnerable to resource exhaustion attacks, it can effectively disable virtual machine management capabilities and potentially impact the entire virtualization host.
From an operational impact perspective, this vulnerability poses substantial risks to virtualization environments that rely on libvirt for management and orchestration. The resource exhaustion can lead to complete service disruption, requiring manual intervention to restore normal operations. Organizations utilizing virtualized infrastructures may experience cascading failures as compromised virtual machines affect other systems in the environment. The vulnerability's ability to trigger through multiple pathways increases its exploitability and makes it particularly dangerous in production environments where virtualization platforms handle critical workloads. Security teams must consider this vulnerability as part of their broader threat landscape, particularly in environments with high virtualization density.
The mitigation strategy for CVE-2018-1064 requires immediate patching of affected libvirt installations to version 4.2.0-rc1 or later, which contains the complete fix for both the original CVE-2018-5748 and this subsequent vulnerability. Organizations should implement monitoring solutions to detect unusual resource consumption patterns that might indicate exploitation attempts. Network segmentation and access controls should be strengthened around virtualization management interfaces to limit potential attack vectors. The vulnerability aligns with CWE-400 which categorizes resource exhaustion flaws, and its exploitation techniques correspond to ATT&CK tactics involving service disruption and denial of service operations. System administrators should also conduct thorough vulnerability assessments of their virtualization environments to identify any other components that might be susceptible to similar issues, particularly those that interface with guest agents or monitor systems.