CVE-2020-36394 : Exploit Details and Defense Strategies

A vulnerability in the Linux-PAM module pam_setquota allows local attackers to manipulate filesystem quotas under certain conditions.

Understanding CVE-2020-36394

This CVE entry describes a security issue in the pam_setquota module of Linux-PAM.

What is CVE-2020-36394?

The vulnerability in pam_setquota.c enables local attackers to adjust their quota on any filesystem when their home directory is a FUSE filesystem mounted under /home.

The Impact of CVE-2020-36394

The vulnerability could be exploited by local attackers to manipulate filesystem quotas, potentially leading to unauthorized resource usage or denial of service.

Technical Details of CVE-2020-36394

The technical aspects of the CVE-2020-36394 vulnerability are outlined below:

Vulnerability Description

The pam_setquota module in Linux-PAM before 2020-05-29 allows local attackers to set their quota on an arbitrary filesystem under specific conditions.

Affected Systems and Versions

Product: Not applicable
Vendor: Not applicable
Versions: Not applicable

Exploitation Mechanism

The vulnerability can be exploited by local attackers whose home directory is a FUSE filesystem mounted under /home.

Mitigation and Prevention

To address CVE-2020-36394, consider the following mitigation strategies:

Immediate Steps to Take

Monitor filesystem quotas regularly to detect any unauthorized changes.
Restrict access to sensitive filesystems to trusted users only.

Long-Term Security Practices

Implement least privilege access controls to limit the impact of potential attacks.
Regularly update and patch the Linux-PAM module to mitigate known vulnerabilities.
Educate users on secure filesystem management practices.

Patching and Updates

Ensure that the Linux-PAM module is updated to a version released after 2020-05-29 to address the vulnerability.