CVE-2019-3881 Explained : Impact and Mitigation

CVE-2019-3881 is a vulnerability in Bundler before version 2.1.0 that could allow an attacker to insert harmful code into a directory with insecure privileges, potentially leading to code execution.

Understanding CVE-2019-3881

What is CVE-2019-3881?

Before version 2.1.0, Bundler had a security issue where it stored gems in an insecure /tmp/ directory when the user's home directory was not writable. This vulnerability could be exploited by an attacker to inject malicious code.

The Impact of CVE-2019-3881

This vulnerability could lead to the execution of malicious code on the system, compromising its integrity and potentially leading to further attacks.

Technical Details of CVE-2019-3881

Vulnerability Description

Bundler versions before 2.1.0 used an insecure pathway in the /tmp/ directory to store gems when the user's home directory was not writable, posing a security risk.

Affected Systems and Versions

Vendor: n/a
Product: rubygem-bundler
Affected Versions: Bundler versions before 2.1.0

Exploitation Mechanism

An attacker could exploit this vulnerability by inserting harmful code into the insecurely stored gems directory, which could then be loaded and executed.

Mitigation and Prevention

Immediate Steps to Take

Upgrade Bundler to version 2.1.0 or newer to mitigate this vulnerability.
Ensure that the user's home directory has proper write permissions to prevent the insecure gem storage.

Long-Term Security Practices

Regularly update software and dependencies to patch known vulnerabilities.
Implement proper file system permissions to restrict unauthorized access.

Patching and Updates

Stay informed about security updates for Bundler and apply patches promptly to secure the system.