CVE-2013-4956 in Puppet
Summary
by MITRE
Puppet Module Tool (PMT), as used in Puppet 2.7.x before 2.7.23 and 3.2.x before 3.2.4, and Puppet Enterprise 2.8.x before 2.8.3 and 3.0.x before 3.0.1, installs modules with weak permissions if those permissions were used when the modules were originally built, which might allow local users to read or modify those modules depending on the original permissions.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 01/04/2022
The vulnerability identified as CVE-2013-4956 affects Puppet Module Tool (PMT) across multiple versions of Puppet and Puppet Enterprise, specifically impacting installations where modules are installed with insufficiently restrictive file permissions. This issue arises from the tool's failure to properly enforce secure default permissions when installing modules, instead preserving the original permissions that were set during module creation. The flaw exists in Puppet 2.7.x versions prior to 2.7.23, 3.2.x versions prior to 3.2.4, and Puppet Enterprise versions 2.8.x prior to 2.8.3 and 3.0.x prior to 3.0.1, creating a persistent security weakness that could be exploited by local adversaries.
The technical root cause of this vulnerability stems from improper permission handling within the module installation process where PMT does not override or enforce secure default permissions when installing modules. When modules are built with certain permissions that may include world-readable or world-writable attributes, these permissions are preserved during installation rather than being reset to secure defaults. This behavior creates a scenario where local users who have access to the system can potentially read or modify module files that should remain protected, depending entirely on how the original module was packaged and what permissions were assigned to its constituent files. The vulnerability specifically relates to CWE-732, which addresses inadequate permissions for critical resources, and represents a failure to implement proper access control mechanisms during software installation processes.
The operational impact of this vulnerability is significant for organizations relying on Puppet for configuration management, as it creates potential attack vectors for local privilege escalation and information disclosure. An attacker with local access to a system running affected Puppet versions could exploit this weakness to read sensitive configuration data, module code, or other potentially confidential information contained within installed modules. Additionally, the ability to modify module files could allow an attacker to inject malicious code or alter system configurations, potentially leading to broader compromise of the affected systems. The risk is particularly elevated in environments where Puppet modules contain sensitive credentials, encryption keys, or other confidential data that should remain protected from unauthorized access.
Organizations should immediately upgrade to patched versions of Puppet and Puppet Enterprise where this vulnerability has been addressed, specifically targeting Puppet 2.7.23, 3.2.4, and the corresponding Puppet Enterprise releases. System administrators should also conduct thorough audits of existing module installations to identify any modules that may have been installed with weak permissions and remediate these issues through manual permission adjustments. The implementation of proper file permission controls during module installation should be enforced through configuration management policies and regular security assessments. Organizations should consider implementing additional monitoring and alerting mechanisms to detect unauthorized modifications to Puppet modules and maintain comprehensive logging of module installation activities to support incident response efforts. This vulnerability highlights the critical importance of secure default configurations and proper access control enforcement in configuration management tools, aligning with ATT&CK technique T1068 which addresses local privilege escalation through insecure file permissions.