CVE-2013-3567 in Suse Linux Enterprise Server
Summary
by MITRE
Puppet 2.7.x before 2.7.22 and 3.2.x before 3.2.2, and Puppet Enterprise before 2.8.2, deserializes untrusted YAML, which allows remote attackers to instantiate arbitrary Ruby classes and execute arbitrary code via a crafted REST API call.
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Analysis
by VulDB Data Team • 01/04/2022
The vulnerability identified as CVE-2013-3567 represents a critical deserialization flaw in the Puppet configuration management system that affects multiple versions of both the open-source Puppet software and Puppet Enterprise. This vulnerability resides in the REST API implementation where the system processes untrusted YAML data without proper sanitization or validation, creating a pathway for remote code execution. The flaw specifically impacts Puppet versions 2.7.x prior to 2.7.22, 3.2.x prior to 3.2.2, and Puppet Enterprise versions prior to 2.8.2, making it a widespread issue affecting organizations relying on these configurations.
The technical root cause of this vulnerability stems from the improper handling of YAML deserialization within the Puppet REST API endpoints. When the system receives YAML data through API calls, it automatically deserializes the content without verifying the source or validating the class types being instantiated. This behavior allows malicious actors to craft specially formatted YAML payloads that, when processed, trigger the instantiation of arbitrary Ruby classes and subsequently execute arbitrary code on the target system. The vulnerability directly maps to CWE-502, which describes the weakness of deserializing untrusted data, and aligns with ATT&CK technique T1059.007 for command and script injection through Ruby-based systems.
The operational impact of this vulnerability is severe and far-reaching, as it provides remote attackers with complete system compromise capabilities. An attacker exploiting this vulnerability can execute arbitrary commands with the privileges of the Puppet service account, potentially leading to full system takeover, data exfiltration, or lateral movement within the network. Given that Puppet is widely used for system configuration management and automation, a successful exploitation could affect multiple systems simultaneously, especially in environments where Puppet is used to manage critical infrastructure components. The vulnerability essentially allows attackers to bypass traditional access controls and gain unauthorized execution privileges within the managed environment.
Organizations affected by this vulnerability should immediately implement the remediation measures provided by Puppet, including upgrading to the patched versions 2.7.22, 3.2.2, and 2.8.2 respectively for Puppet and Puppet Enterprise. Additional mitigations should include network-level restrictions to limit access to the Puppet REST API endpoints, implementing proper input validation at the application level, and monitoring for suspicious API activity. Security teams should also consider implementing network segmentation to isolate Puppet servers from critical production systems and establish automated patch management processes to ensure timely deployment of security updates. The vulnerability demonstrates the importance of secure deserialization practices and proper input validation in enterprise configuration management systems, highlighting the need for comprehensive security testing of all data processing pathways within critical infrastructure software.