CVE-2016-3108 in Pulp
Summary
by MITRE
The pulp-gen-nodes-certificate script in Pulp before 2.8.3 allows local users to leak the keys or write to arbitrary files via a symlink attack.
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Analysis
by VulDB Data Team • 12/08/2022
The vulnerability identified as CVE-2016-3108 affects the pulp-gen-nodes-certificate script within the Pulp content management system prior to version 2.8.3. This issue represents a significant security flaw that enables local attackers to exploit symbolic link manipulation techniques to either extract sensitive cryptographic keys or write to arbitrary files within the system. The vulnerability stems from insufficient validation of symbolic link references during certificate generation processes, creating an attack surface that can be leveraged by malicious users with local access to the system.
The technical implementation of this vulnerability involves the script's failure to properly validate file paths when processing symbolic links during certificate generation. When the pulp-gen-nodes-certificate script processes certificate-related operations, it does not adequately check whether file paths contain symbolic links that could be manipulated by an attacker. This allows a local user to create malicious symbolic links that point to sensitive files such as private key stores or configuration files, enabling either information disclosure through key leakage or arbitrary file writing through crafted symlink targets. The flaw directly relates to CWE-367, which addresses time-of-check to time-of-use vulnerabilities, where the system's behavior changes between the time a check is performed and when the action is executed.
From an operational perspective, this vulnerability poses substantial risks to organizations using Pulp for content management and distribution. Attackers with local system access can exploit this weakness to extract cryptographic keys that may be used for authentication, encryption, or digital signatures within the Pulp environment. The potential for arbitrary file writing creates additional attack vectors where malicious actors could modify critical system files, configuration data, or certificate stores to gain further privileges or disrupt service operations. The impact extends beyond immediate key leakage to potential privilege escalation and system compromise, particularly in environments where Pulp manages sensitive content or serves as a critical component in content delivery infrastructure.
Organizations should implement immediate mitigations including upgrading to Pulp version 2.8.3 or later, which contains the necessary fixes for this vulnerability. Additionally, system administrators should review and restrict permissions for the pulp-gen-nodes-certificate script, ensuring that it operates with minimal necessary privileges and that symbolic link handling is properly validated. Security monitoring should include detection of suspicious symbolic link creation patterns and file access anomalies during certificate generation processes. The vulnerability aligns with ATT&CK technique T1059.001 for execution through command-line interfaces and T1566.001 for privilege escalation through local exploitation. Organizations should also consider implementing file integrity monitoring solutions to detect unauthorized modifications to certificate files and key stores that could indicate successful exploitation of this vulnerability.