CVE-2012-3537 in Crowbar
Summary
by MITRE
The Crowbar Ohai plugin (chef/cookbooks/ohai/files/default/plugins/crowbar.rb) in the Deployer Barclamp in Crowbar, possibly 1.4 and earlier, allows local users to execute arbitrary shell commands via vectors related to "insecure handling of tmp files" and predictable file names.
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Analysis
by VulDB Data Team • 12/13/2021
The vulnerability identified as CVE-2012-3537 resides within the Crowbar Ohai plugin, specifically in the Deployer Barclamp component of the Crowbar infrastructure management platform. This issue affects versions 1.4 and earlier, representing a critical security flaw that enables local users to execute arbitrary shell commands through improper handling of temporary files. The vulnerability stems from the insecure management of temporary file creation and naming conventions, creating a pathway for privilege escalation and command injection attacks.
The technical flaw manifests through the insecure handling of temporary files within the ohai plugin implementation. When the Crowbar system processes certain operations, it creates temporary files with predictable names and locations, allowing local users to manipulate these files before they are processed by the system. This predictable file naming scheme, combined with inadequate file permissions and security checks during temporary file creation, enables attackers to substitute malicious content for legitimate temporary files. The vulnerability operates at the file system level where temporary files are created without proper security measures such as secure temporary file creation functions or randomized naming schemes.
This vulnerability has significant operational impact on systems utilizing Crowbar for infrastructure deployment and management. Local users who can access the system can leverage this flaw to execute arbitrary commands with the privileges of the user running the ohai plugin, potentially escalating to higher privilege levels depending on the system configuration. The attack vector is particularly dangerous because it requires minimal privileges and can be exploited by users who already have access to the system, making it a serious concern for environments where privilege separation is not strictly enforced. The implications extend beyond simple command execution to potential system compromise and data exfiltration.
The vulnerability aligns with CWE-377 and CWE-378, which address insecure temporary file creation and predictable temporary file names respectively. From an ATT&CK framework perspective, this vulnerability maps to T1059.001 for command and scripting interpreter and T1068 for exploit for privilege escalation. The attack chain typically involves local users creating malicious temporary files with predictable names, which are then processed by the vulnerable ohai plugin, leading to arbitrary code execution. Organizations should implement proper temporary file handling practices including secure file creation with proper permissions, randomization of temporary file names, and validation of file contents before processing.
Mitigation strategies for CVE-2012-3537 require immediate patching of affected Crowbar versions to address the insecure temporary file handling in the ohai plugin. System administrators should also implement proper temporary file management practices, including using secure temporary file creation functions, implementing proper file permissions, and avoiding predictable naming schemes for temporary files. Network segmentation and privilege separation can help limit the impact of such vulnerabilities, while monitoring for suspicious temporary file creation patterns can aid in detecting potential exploitation attempts. Organizations should also conduct thorough security assessments of their Crowbar implementations to identify similar vulnerabilities in other components of the infrastructure management platform.