CVE-2018-0023 in JSNAPy
Summary
by MITRE
JSNAPy is an open source python version of Junos Snapshot Administrator developed by Juniper available through github. The default configuration and sample files of JSNAPy automation tool versions prior to 1.3.0 are created world writable. This insecure file and directory permission allows unprivileged local users to alter the files under this directory including inserting operations not intended by the package maintainer, system administrator, or other users. This issue only affects users who downloaded and installed JSNAPy from github.
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Analysis
by VulDB Data Team • 02/27/2023
CVE-2018-0023 represents a critical privilege escalation vulnerability in JSNAPy, an open-source automation tool developed by Juniper for network configuration management. This vulnerability stems from insecure default file permissions that were improperly configured in versions prior to 1.3.0, creating a persistent security weakness that affects local users with minimal privileges. The flaw manifests when the tool's default configuration and sample files are created with world-writable permissions, allowing any local user to modify critical operational components. This issue directly maps to CWE-732, which specifically addresses incorrect permissions for critical resources, and aligns with ATT&CK technique T1068, which covers local privilege escalation through insecure file permissions. The vulnerability impacts the integrity of the automation framework by enabling unauthorized modification of configuration files that control network device operations, potentially allowing attackers to inject malicious commands or alter network behavior without proper authorization.
The technical implementation of this vulnerability occurs at the filesystem level where JSNAPy's installation process fails to properly set restrictive permissions on its configuration directories and files. When users download and install JSNAPy from GitHub, the tool creates default directories and sample files with overly permissive settings that permit write access to all local users. This misconfiguration creates a persistent backdoor that remains active until the system is properly patched or the permissions are manually corrected. The flaw specifically affects the tool's ability to maintain secure operational integrity since configuration files control the execution of network automation tasks, making them prime targets for malicious modification. Attackers can exploit this weakness by inserting unauthorized operations into the configuration files, potentially leading to unauthorized network access, data exfiltration, or disruption of network services. The vulnerability demonstrates poor security hygiene in the tool's installation process and highlights the importance of proper privilege management in automation frameworks.
The operational impact of CVE-2018-0023 extends beyond simple file modification, as it compromises the fundamental security model of network automation tools that rely on trusted configuration files. Unprivileged local users can effectively subvert the intended security posture of network administrators who depend on JSNAPy for consistent and secure network device management. This vulnerability enables attackers to manipulate the automation workflow by introducing malicious operations that execute with the privileges of the JSNAPy process, potentially leading to unauthorized access to network devices or modification of critical network configurations. The risk is particularly elevated in enterprise environments where multiple users share systems and where network automation tools are frequently deployed. Organizations using JSNAPy for network management may experience unauthorized changes to device configurations, leading to potential service disruptions, security breaches, or compliance violations. The vulnerability also creates a persistent threat vector that remains active until properly addressed, making it particularly dangerous for environments where system administrators may not immediately detect the compromise.
Mitigation strategies for CVE-2018-0023 focus on immediate remediation through version updates and manual permission corrections. The most effective solution involves upgrading to JSNAPy version 1.3.0 or later, where the insecure default permissions have been corrected. Organizations should also implement manual verification of file permissions on existing installations, ensuring that configuration directories and files are owned by appropriate system users and have restrictive permissions set. System administrators should conduct comprehensive audits of all JSNAPy installations to identify and correct insecure permissions manually. Additionally, implementing automated monitoring solutions that track unauthorized modifications to critical configuration files can help detect exploitation attempts. Security best practices recommend establishing baseline configurations with proper ownership and permissions before installing JSNAPy, following the principle of least privilege. Organizations should also consider implementing file integrity monitoring tools that can alert on unauthorized changes to critical system files. The vulnerability serves as a reminder of the importance of secure default configurations in automation tools and the need for continuous security assessment of open-source projects used in enterprise environments.