CVE-2014-0134 in Compute
Summary
by MITRE
The instance rescue mode in OpenStack Compute (Nova) 2013.2 before 2013.2.3 and Icehouse before 2014.1, when using libvirt to spawn images and use_cow_images is set to false, allows remote authenticated users to read certain compute host files by overwriting an instance disk with a crafted image.
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Analysis
by VulDB Data Team • 03/21/2022
The vulnerability identified as CVE-2014-0134 represents a critical security flaw in OpenStack Compute (Nova) that specifically affects versions prior to 2013.2.3 and Icehouse before 2014.1. This issue manifests within the instance rescue mode functionality, which is designed to provide administrators with the ability to troubleshoot and recover virtual machine instances when normal operations fail. The vulnerability occurs under specific configuration conditions where libvirt is used to spawn images and the use_cow_images parameter is explicitly set to false, creating a dangerous operational scenario that exposes sensitive system files to unauthorized access.
The technical exploitation of this vulnerability involves a sophisticated attack vector that leverages the instance rescue mode's disk handling mechanisms. When an authenticated attacker with appropriate privileges attempts to rescue an instance, the system fails to properly validate or sanitize the disk image being used for the rescue operation. This flaw allows attackers to craft malicious disk images that, when used in the rescue process, can overwrite the instance disk in a manner that exposes underlying host filesystem contents. The vulnerability specifically targets the lack of proper file access controls and validation during the disk image processing phase, enabling attackers to read files that should remain protected within the compute host's filesystem hierarchy.
The operational impact of this vulnerability extends beyond simple information disclosure, as it fundamentally compromises the isolation guarantees that virtualized environments are designed to provide. Attackers can potentially access sensitive system files, configuration data, and potentially even other virtual machine instances running on the same host. This breach of isolation represents a severe violation of cloud security principles and could lead to privilege escalation, data exfiltration, and further compromise of the underlying infrastructure. The vulnerability is particularly dangerous in multi-tenant cloud environments where proper segregation between different users and instances is critical for maintaining security boundaries and compliance requirements.
The attack surface for this vulnerability is primarily limited to authenticated users with sufficient privileges to initiate rescue operations, but this access level is often available to cloud administrators or users with appropriate roles within the OpenStack deployment. This makes the vulnerability particularly concerning as it can be exploited by insiders or attackers who have gained legitimate access to the cloud platform. The configuration requirement of use_cow_images set to false creates a specific attack scenario that organizations may not immediately recognize as a security risk, making the vulnerability more insidious and harder to detect.
Organizations affected by this vulnerability should prioritize immediate remediation through patching to versions 2013.2.3 or Icehouse 2014.1 and later, which contain the necessary fixes to address the improper validation of disk images during rescue operations. Additionally, security teams should implement strict monitoring of rescue mode usage and establish proper access controls to limit who can initiate these operations. The vulnerability aligns with CWE-22 (Improper Limitation of a Pathname to a Restricted Directory) and CWE-264 (Permissions, Privileges, and Access Controls) categories, while also mapping to ATT&CK technique T1059 (Command and Scripting Interpreter) and T1078 (Valid Accounts) as attackers may use this vulnerability to escalate privileges or access additional system resources. Organizations should also consider implementing network segmentation and additional logging controls around virtualization management interfaces to detect and prevent unauthorized access to rescue functionality.