CVE-2014-3703 in PackStack
Summary
by MITRE
OpenStack PackStack 2012.2.1, when the Open vSwitch (OVS) monolithic plug-in is not used, does not properly set the libvirt_vif_driver configuration option when generating the nova.conf configuration, which causes the firewall to be disabled and allows remote attackers to bypass intended access restrictions.
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Analysis
by VulDB Data Team • 04/04/2022
The vulnerability identified as CVE-2014-3703 affects OpenStack PackStack version 2012.2.1 and represents a critical configuration flaw that undermines network security controls within OpenStack deployments. This issue specifically impacts installations that utilize Open vSwitch (OVS) with the non-monolithic plugin configuration, creating a dangerous misconfiguration that directly compromises the security architecture of virtualized environments. The flaw stems from improper handling of the libvirt_vif_driver parameter during nova.conf generation, which serves as a fundamental component in OpenStack's virtual network interface management and security policy enforcement.
The technical root cause of this vulnerability lies in the incorrect configuration of the libvirt_vif_driver setting within the nova.conf file, which controls how virtual network interfaces are managed and secured within the libvirt hypervisor environment. When PackStack generates the nova.conf configuration without properly setting this parameter, it defaults to a configuration that disables the firewall rules enforcement mechanisms that should normally protect virtual machine network traffic. This misconfiguration creates a pathway for remote attackers to bypass access controls that would typically be enforced by OpenStack's security framework, effectively removing the network isolation that virtual machines should maintain from each other and from external network resources.
The operational impact of this vulnerability extends beyond simple network access bypass, as it fundamentally undermines the security model of OpenStack deployments. Attackers can exploit this weakness to perform network reconnaissance, lateral movement, and potentially gain unauthorized access to sensitive virtual machine resources within the same OpenStack environment. The vulnerability affects the core security controls that protect against man-in-the-middle attacks, network scanning, and other malicious activities that rely on network isolation principles. This flaw particularly impacts cloud environments where multiple tenants share the same infrastructure, as it removes the network segmentation that should prevent tenant-to-tenant communication and data leakage.
This vulnerability maps directly to CWE-276, which addresses improper privileges and access control issues, and aligns with ATT&CK technique T1046 for network service scanning and T1071 for application layer protocol usage. The misconfiguration creates a persistent security weakness that remains active until manually corrected, making it particularly dangerous in automated deployment environments. Organizations using OpenStack with PackStack deployments should immediately implement configuration audits to verify that the libvirt_vif_driver parameter is correctly set to appropriate values such as nova.virt.libvirt.vif.LibvirtGenericVIFDriver or similar secure implementations. The fix requires manual intervention to correct the nova.conf file generation process or to manually set the proper configuration parameters after PackStack installation. This vulnerability highlights the critical importance of proper configuration management in cloud infrastructure deployments and demonstrates how seemingly minor configuration errors can create significant security weaknesses that directly impact the integrity and confidentiality of virtualized environments.