CVE-2012-1988 in Puppet Enterprise Users
Summary
by MITRE
Puppet 2.6.x before 2.6.15 and 2.7.x before 2.7.13, and Puppet Enterprise (PE) Users 1.0, 1.1, 1.2.x, 2.0.x, and 2.5.x before 2.5.1 allows remote authenticated users with agent SSL keys and file-creation permissions on the puppet master to execute arbitrary commands by creating a file whose full pathname contains shell metacharacters, then performing a filebucket request.
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Analysis
by VulDB Data Team • 12/03/2021
The vulnerability described in CVE-2012-1988 represents a critical command injection flaw within the puppet configuration management system that affects multiple versions of both open source puppet and puppet enterprise. This security issue stems from inadequate input validation and sanitization within the filebucket functionality of puppet master servers, creating a pathway for authenticated attackers to execute arbitrary code on the system. The vulnerability specifically targets environments where puppet agents maintain SSL certificates and possess file creation permissions on the puppet master, making it particularly dangerous in production environments where these conditions are commonly met.
The technical flaw manifests when an authenticated attacker with agent SSL keys and file creation privileges on the puppet master creates a malicious file with a pathname containing shell metacharacters. When the puppet master processes this file through a filebucket request, the system fails to properly sanitize the pathname before executing shell commands, allowing the attacker to inject and execute arbitrary commands with the privileges of the puppet master process. This represents a classic command injection vulnerability that leverages the legitimate filebucket functionality to bypass normal security controls, with the attack vector exploiting the trust relationship between puppet agents and the master server.
The operational impact of this vulnerability extends far beyond simple privilege escalation, as successful exploitation can lead to complete compromise of the puppet master server and potentially the entire infrastructure managed by that puppet environment. Attackers can leverage this vulnerability to execute malicious commands, establish persistent backdoors, exfiltrate sensitive configuration data, or manipulate the puppet master's file system to disrupt service availability. The vulnerability affects both puppet 2.6.x and 2.7.x versions as well as puppet enterprise users, indicating a widespread issue that would impact numerous organizations relying on puppet for infrastructure automation and configuration management. This vulnerability aligns with CWE-78, which describes improper neutralization of special elements used in shell commands, and represents a significant risk to organizations using puppet in production environments.
Organizations affected by this vulnerability should immediately implement mitigations including upgrading to patched versions of puppet 2.6.15, 2.7.13, or puppet enterprise 2.5.1 and later releases. Additional protective measures should include restricting file creation permissions on the puppet master for puppet agents, implementing strict input validation for file paths, and monitoring for suspicious filebucket activities. Network segmentation and privilege separation can help limit the blast radius if exploitation occurs, while regular security audits of puppet master configurations should verify that only necessary agents have file creation capabilities. This vulnerability demonstrates the importance of proper input sanitization in systems that process user-supplied data through shell execution contexts, and serves as a reminder of the critical security considerations when implementing configuration management systems in enterprise environments.