CVE-2015-8768 in click
Summary
by MITRE
install.py in click allows remote attackers to gain privileges via a data tarball containing a file with a crafted path.
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Analysis
by VulDB Data Team • 11/14/2022
The vulnerability identified as CVE-2015-8768 affects the click Python package version 6.0 and earlier, specifically within the install.py script that handles data tarball extraction processes. This flaw represents a classic path traversal vulnerability that enables remote attackers to manipulate file extraction operations and potentially execute arbitrary code with elevated privileges. The vulnerability occurs when the install.py script processes tarball archives containing files with crafted paths that can bypass normal extraction safeguards.
The technical implementation of this vulnerability stems from inadequate input validation during tarball processing within the click package's installation mechanism. When the script extracts files from a data tarball, it fails to properly sanitize or validate file paths contained within the archive, allowing attackers to specify paths that traverse outside the intended extraction directory. This behavior aligns with CWE-22 Path Traversal vulnerabilities, specifically categorized under directory traversal attacks that exploit insufficient restrictions on file paths. The flaw essentially permits attackers to write files to arbitrary locations on the target system, potentially overwriting critical system files or installing malicious components.
The operational impact of CVE-2015-8768 extends beyond simple privilege escalation to encompass broader system compromise potential. An attacker who can influence the contents of a data tarball used by click during installation can execute code with the privileges of the user running the installation process. This scenario commonly occurs in environments where automated deployment tools or package managers download and install packages from untrusted sources. The vulnerability can be exploited through supply chain attacks where malicious actors compromise package repositories or directly modify packages before distribution, creating a persistent threat vector that affects all systems using vulnerable versions of click.
Organizations and developers should prioritize immediate mitigation through version updates to click package versions 6.1 and later, which contain patches addressing the path traversal vulnerability. System administrators should implement strict package repository validation and verification procedures, including checksum validation and digital signature verification of all downloaded packages. Additionally, the vulnerability demonstrates the importance of secure coding practices in package management tools, particularly regarding file path handling and input validation. This issue aligns with ATT&CK technique T1195.002 for Supply Chain Compromise and emphasizes the critical need for maintaining secure software development lifecycle practices. The vulnerability also underscores the necessity of implementing principle of least privilege for package installation processes and regular security auditing of dependency management systems to prevent exploitation of similar flaws in other components of the software supply chain.