CVE-2019-20384 : Exploit Details and Defense Strategies

Gentoo Portage through version 2.3.84 allows local users to exploit a vulnerability to insert a malicious plugin in the /usr/lib64/nagios/plugins directory by leveraging access to the nagios user account.

Understanding CVE-2019-20384

This CVE involves a security issue in Gentoo Portage that enables local users to compromise the system by placing a Trojan horse plugin in a specific directory.

What is CVE-2019-20384?

Local users can abuse a vulnerability in Gentoo Portage up to version 2.3.84 to insert a malicious plugin in the /usr/lib64/nagios/plugins directory by utilizing the access provided to the nagios user account.

The Impact of CVE-2019-20384

The ability to write files to the specified directory occurs during the timeframe between a call to emake and a call to fowners, potentially leading to unauthorized access and malicious activities.

Technical Details of CVE-2019-20384

This section provides detailed technical information about the vulnerability.

Vulnerability Description

Gentoo Portage up to version 2.3.84 is susceptible to a security flaw that allows local users to plant a malicious plugin in the /usr/lib64/nagios/plugins directory by exploiting the permissions associated with the nagios user account.

Affected Systems and Versions

Systems running Gentoo Portage up to version 2.3.84

Exploitation Mechanism

Local users can take advantage of the writable permissions in the /usr/lib64/nagios/plugins directory during specific system calls to emake and fowners.

Mitigation and Prevention

Protect your systems from CVE-2019-20384 with the following measures:

Immediate Steps to Take

Monitor and restrict access to the /usr/lib64/nagios/plugins directory
Implement least privilege principles for user accounts
Regularly audit and review file permissions and ownership

Long-Term Security Practices

Conduct regular security training for users on safe practices
Keep systems and software up to date with the latest patches and security updates

Patching and Updates

Apply patches and updates provided by Gentoo Portage to address the vulnerability