CVE-2015-8860 in tar Package
Summary
by MITRE
The tar package before 2.0.0 for Node.js allows remote attackers to write to arbitrary files via a symlink attack in an archive.
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Analysis
by VulDB Data Team • 05/14/2026
The vulnerability identified as CVE-2015-8860 affects the tar package version 2.0.0 and earlier in the Node.js ecosystem, presenting a critical security risk that enables remote attackers to perform arbitrary file write operations through malicious symlink attacks within archived files. This flaw specifically exploits the insecure handling of symbolic links during archive extraction processes, creating a path traversal scenario that can be leveraged by attackers to write files to locations outside the intended extraction directory.
The technical implementation of this vulnerability stems from the tar package's failure to properly validate and resolve symbolic links when extracting archive contents. When an attacker crafts a malicious archive containing symbolic links that point to arbitrary file paths, the extraction process follows these links without adequate sanitization, allowing the attacker to write data to any location on the target system where the application has write permissions. This behavior directly violates the principle of least privilege and enables attackers to overwrite critical system files, inject malicious code, or establish persistence mechanisms. The vulnerability operates at the file system level and can be exploited through various attack vectors including package installation, file extraction, or archive processing operations within Node.js applications.
The operational impact of CVE-2015-8860 is severe and far-reaching across the Node.js ecosystem, as the tar package is widely used for handling compressed archives and package installations. Attackers can exploit this vulnerability to compromise systems by writing malicious files to critical directories such as /usr/bin, /etc, or application directories, potentially leading to privilege escalation, persistent backdoors, or complete system compromise. The vulnerability is particularly dangerous in automated environments where package installations occur without manual oversight, as attackers can silently install malicious code during legitimate package updates or dependency installations. This flaw also affects containerized environments and CI/CD pipelines where automated extraction processes are common, making it a significant concern for DevOps and security operations teams.
Security mitigations for CVE-2015-8860 primarily involve upgrading to tar package version 2.0.0 or later, which implements proper symlink validation and extraction safeguards. Organizations should conduct comprehensive vulnerability assessments to identify systems running affected versions and ensure all Node.js applications are updated to use secure tar implementations. Additional protective measures include implementing strict file system permissions, using sandboxed environments for archive processing, and deploying automated scanning tools to detect malicious archive content. From a cybersecurity framework perspective, this vulnerability aligns with CWE-59 and CWE-22, representing weaknesses in file path resolution and path traversal attacks. The attack pattern corresponds to techniques documented in the MITRE ATT&CK framework under T1059 for command and script interpreters and T1074 for data staging, as attackers can leverage this vulnerability to stage malicious payloads and establish persistence within target environments. Organizations should also consider implementing network-level controls and monitoring for suspicious file write activities that may indicate exploitation attempts.