CVE-2021-3155 : What You Need to Know

This article provides detailed information about CVE-2021-3155, a vulnerability in snapd that created ~/snap directories with improper permissions, potentially exposing private information to attackers.

Understanding CVE-2021-3155

This section delves into the details of the CVE-2021-3155 vulnerability affecting snapd.

What is CVE-2021-3155?

snapd versions 2.54.2 and earlier inadvertently created ~/snap directories with permissions that could allow local attackers to access private information. The issue has been addressed in snapd versions 2.54.3+18.04, 2.54.3+20.04, and 2.54.3+21.10.1.

The Impact of CVE-2021-3155

The vulnerability could enable unauthorized users to read sensitive data that should have been protected, potentially leading to privacy breaches and information exposure.

Technical Details of CVE-2021-3155

Explore the technical aspects of the CVE-2021-3155 vulnerability in snapd.

Vulnerability Description

The flaw in snapd versions 2.54.2 and earlier allowed the creation of ~/snap directories without proper owner-only permissions, opening the door for local attackers to exploit this misconfiguration.

Affected Systems and Versions

Users running snapd versions less than or equal to 2.54.2 are impacted by this vulnerability, particularly affecting Canonical Ltd.'s snapd products with custom versions.

Exploitation Mechanism

Local attackers could exploit the too-wide permissions on ~/snap directories created by vulnerable snapd versions to gain access to information meant to be private.

Mitigation and Prevention

Learn about the mitigation strategies and preventive measures for CVE-2021-3155.

Immediate Steps to Take

Users should upgrade to the fixed versions, 2.54.3+18.04, 2.54.3+20.04, or 2.54.3+21.10.1, to address the vulnerability and ensure proper permissions on ~/snap directories.

Long-Term Security Practices

Implement best security practices, such as regularly updating snapd and monitoring permission settings on critical directories, to enhance overall system security.

Patching and Updates

Stay informed about security updates from Canonical Ltd. and promptly apply patches to mitigate potential risks associated with vulnerabilities like CVE-2021-3155.