CVE-2021-3156 Explained : Impact and Mitigation

A heap-based buffer overflow vulnerability, known as Baron Samedit, exists in Sudo before version 1.9.5p2. Exploitation of this vulnerability could allow an attacker to escalate privileges to root via a specific command-line argument.

Understanding CVE-2021-3156

This section provides insights into the critical vulnerability identified as CVE-2021-3156.

What is CVE-2021-3156?

The CVE-2021-3156, also known as Baron Samedit, is an off-by-one error existing in Sudo versions prior to 1.9.5p2. This flaw can be exploited by an attacker to trigger a heap-based buffer overflow, consequently enabling them to elevate their privileges to root when utilizing the 'sudoedit -s' command followed by a command-line argument ending with a single backslash character.

The Impact of CVE-2021-3156

The impact of this vulnerability is critical as it allows malicious actors to achieve privilege escalation to the root user level, potentially leading to unauthorized access and control over the affected system.

Technical Details of CVE-2021-3156

In this section, the technical aspects of the CVE-2021-3156 vulnerability are discussed.

Vulnerability Description

The vulnerability in Sudo before version 1.9.5p2 results from an off-by-one error, leading to a heap-based buffer overflow. This can be exploited for privilege escalation to the root user.

Affected Systems and Versions

Sudo versions prior to 1.9.5p2 are affected by this vulnerability, potentially impacting a wide range of systems utilizing the sudoedit command.

Exploitation Mechanism

Exploiting CVE-2021-3156 involves leveraging the specific scenario of executing the 'sudoedit -s' command with a command-line argument ending in a single backslash character to trigger the heap-based buffer overflow.

Mitigation and Prevention

This section outlines the measures to mitigate and prevent the exploitation of CVE-2021-3156.

Immediate Steps to Take

Immediate mitigation steps include updating Sudo to version 1.9.5p2 or later, applying relevant security patches, and monitoring for any unauthorized system activity.

Long-Term Security Practices

Implementing least privilege access, regular security assessments, and user training on secure system practices can enhance long-term security posture.

Patching and Updates

Regularly check for updates from the official Sudo project website and other relevant security advisories to ensure timely patching of vulnerabilities and overall system security.