CVE-2012-3361 in Diablo
Summary
by MITRE
virt/disk/api.py in OpenStack Compute (Nova) Folsom (2012.2), Essex (2012.1), and Diablo (2011.3) allows remote authenticated users to overwrite arbitrary files via a symlink attack on a file in an image.
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Analysis
by VulDB Data Team • 12/06/2021
The vulnerability identified as CVE-2012-3361 represents a critical file system security flaw within OpenStack Compute (Nova) versions Folsom, Essex, and Diablo. This issue stems from improper handling of symbolic links during image processing operations, creating a path traversal scenario that allows authenticated remote attackers to manipulate file system contents. The vulnerability specifically affects the virt/disk/api.py component which manages disk image operations, making it a core element of the cloud infrastructure's storage management system. Attackers exploiting this weakness can leverage the symlink attack to overwrite arbitrary files on the host system, potentially compromising the integrity and availability of the entire cloud environment.
The technical implementation of this vulnerability involves the manipulation of symbolic link references during image processing workflows within the Nova compute service. When processing disk images, the system fails to properly validate or sanitize symbolic link paths, allowing attackers to create or manipulate symbolic links that point to sensitive system files. This flaw falls under the CWE-59 category of Improper Link Resolution, specifically targeting the resolution of symbolic links in a manner that can lead to unauthorized file access or modification. The vulnerability operates at the intersection of file system security and cloud infrastructure management, where the privilege escalation occurs through legitimate authenticated access to the Nova service.
Operationally, the impact of CVE-2012-3361 extends far beyond simple file overwrites, as it can lead to complete system compromise and unauthorized access to cloud resources. An authenticated attacker can leverage this vulnerability to modify critical system files, potentially gaining root access to the underlying host system, or to manipulate virtual machine images in ways that could affect multiple tenants within the same cloud deployment. The attack vector requires only remote authenticated access, meaning that once an attacker has valid credentials to the OpenStack environment, they can execute this attack without requiring additional privileges or local system access. This makes the vulnerability particularly dangerous in multi-tenant cloud environments where isolation between users is paramount.
The mitigation strategies for CVE-2012-3361 involve multiple layers of defensive measures that address both the immediate technical flaw and broader security practices. Organizations should immediately upgrade to patched versions of OpenStack Nova that properly handle symbolic link resolution during image processing operations. System administrators should implement strict file system permissions and ensure that image processing operations occur in isolated environments with minimal privileges. The vulnerability demonstrates the importance of proper input validation and path resolution within cloud infrastructure components, aligning with ATT&CK technique T1059.007 for Command and Scripting Interpreter and T1068 for Exploitation for Privilege Escalation. Additionally, organizations should implement monitoring solutions that can detect unusual file system modifications and symbolic link creation activities, as these patterns often indicate exploitation attempts. The fix typically involves implementing proper symlink resolution checks and ensuring that all image processing operations validate file paths before executing any file system modifications, thereby preventing the exploitation path that leads to arbitrary file overwrites.