CVE-2012-1906 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 uses predictable file names when installing Mac OS X packages from a remote source, which allows local users to overwrite arbitrary files or install arbitrary packages via a symlink attack on a temporary file in /tmp.
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Analysis
by VulDB Data Team • 12/03/2021
The vulnerability described in CVE-2012-1906 represents a critical security flaw in Puppet configuration management software affecting versions prior to specific patch releases. This issue specifically impacts Mac OS X package installations where Puppet employs predictable file naming conventions during the installation process from remote sources. The vulnerability stems from insufficient temporary file handling mechanisms that create predictable filenames in the /tmp directory, making the system susceptible to symlink-based attacks.
The technical implementation of this vulnerability exploits the predictable nature of temporary file creation in Puppet's package installation workflow. When Puppet downloads and processes Mac OS X packages from remote repositories, it generates temporary files with known or predictable names within the /tmp directory. This predictable naming pattern allows local attackers to create symbolic links with the same names before Puppet attempts to create the actual temporary files. The attack vector specifically targets the race condition between the creation of the symbolic link by the attacker and the subsequent file operations performed by Puppet.
The operational impact of this vulnerability extends beyond simple privilege escalation as it enables arbitrary file overwrites and unauthorized package installations. An attacker with local access can leverage this vulnerability to replace critical system files with malicious counterparts, effectively compromising the integrity of the target system. The ability to install arbitrary packages through this attack vector means that an attacker could potentially deploy malware, backdoors, or other malicious software directly onto the compromised system. This represents a significant threat to system confidentiality, integrity, and availability within enterprise environments where Puppet is commonly deployed for configuration management.
From a cybersecurity perspective, this vulnerability aligns with CWE-367, which addresses Time-of-Check to Time-of-Use (TOCTOU) race conditions, and specifically relates to the improper handling of temporary files in security-sensitive contexts. The attack pattern described corresponds to techniques found in the MITRE ATT&CK framework under the T1059.007 sub-technique for command and scripting interpreter, where attackers exploit system vulnerabilities to execute malicious code through compromised package installation processes. The vulnerability also demonstrates characteristics consistent with T1546.001, representing privilege escalation through modifications to installed software packages.
Organizations should implement immediate mitigations including upgrading to patched versions of Puppet software, specifically versions 2.6.15 and 2.7.13 for standard Puppet installations, and corresponding releases for Puppet Enterprise users. System administrators should also consider implementing additional controls such as restricting write permissions to the /tmp directory for non-root users, monitoring for suspicious symlink creation patterns, and conducting regular security audits of Puppet configuration files. The remediation process should include comprehensive testing of upgraded environments to ensure that package installation workflows function correctly without reintroducing similar race condition vulnerabilities. Additionally, organizations should review their overall package management policies and consider implementing more robust temporary file handling mechanisms that utilize unique naming conventions or atomic file creation techniques to prevent similar vulnerabilities from emerging in other software components.