CVE-2014-7823 in libvirt
Summary
by MITRE
The virDomainGetXMLDesc API in Libvirt before 1.2.11 allows remote read-only users to obtain the VNC password by using the VIR_DOMAIN_XML_MIGRATABLE flag, which triggers the use of the VIR_DOMAIN_XML_SECURE flag.
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Analysis
by VulDB Data Team • 02/25/2022
The vulnerability identified as CVE-2014-7823 resides within the Libvirt virtualization management library, specifically affecting versions prior to 1.2.11. This flaw represents a significant security weakness that undermines the confidentiality of virtual machine configurations. The issue manifests through the virDomainGetXMLDesc API function, which serves as a critical interface for retrieving domain configuration data in libvirt environments. When remote read-only users interact with this API, they can exploit a specific flag combination to extract sensitive information that should remain protected.
The technical mechanism behind this vulnerability involves the improper handling of XML configuration flags within the libvirt daemon. Specifically, when the VIR_DOMAIN_XML_MIGRATABLE flag is utilized in conjunction with the virDomainGetXMLDesc API, the system automatically triggers the use of the VIR_DOMAIN_XML_SECURE flag internally. This cascade of flag usage results in the inclusion of sensitive VNC password information within the returned XML configuration data. The vulnerability stems from inadequate access control mechanisms that fail to properly sanitize output based on user permissions and flag combinations.
From an operational perspective, this vulnerability creates a serious risk for virtualization environments that rely on libvirt for management. Remote attackers with read-only access can leverage this flaw to extract VNC passwords, potentially enabling them to gain unauthorized access to virtual machine console sessions. The impact extends beyond simple password disclosure, as these credentials could provide attackers with direct access to guest operating systems, bypassing other security controls. This vulnerability particularly affects cloud environments and infrastructure-as-a-service deployments where multiple users share management interfaces.
The vulnerability aligns with CWE-200, which addresses improper exposure of sensitive information, and demonstrates characteristics consistent with CWE-310, focusing on cryptographic weakness. From an ATT&CK framework perspective, this vulnerability maps to T1562.001, which covers "Taint Data" and "Obtain Capabilities", as it allows attackers to extract sensitive data from the system. The flaw also relates to T1078, "Valid Accounts", as it enables unauthorized access through legitimate authentication mechanisms. Organizations implementing libvirt-based virtualization platforms face a substantial risk of credential compromise, particularly in multi-tenant environments where proper isolation is critical.
Mitigation strategies for CVE-2014-7823 require immediate implementation of the libvirt patch version 1.2.11 or later, which addresses the improper flag handling behavior. System administrators should also implement additional controls such as restricting access to the virDomainGetXMLDesc API through firewall rules, implementing role-based access controls, and monitoring for unusual API usage patterns. Organizations should conduct comprehensive audits of their virtualization environments to identify all systems running vulnerable libvirt versions and ensure proper patch management procedures are in place. The vulnerability highlights the importance of proper input validation and output sanitization in virtualization management interfaces, as well as the need for comprehensive testing of flag combinations in API functions that handle sensitive data.