CVE-2021-3726 Explained : Impact and Mitigation

A vulnerability has been identified in the

title

function of

ohmyzsh/ohmyzsh

, which could allow for OS command injection. This CVE, with a CVSS base score of 7.5 (High), could impact the confidentiality, integrity, and availability of affected systems. Here's what you need to know about CVE-2021-3726.

Understanding CVE-2021-3726

This section provides insights into the vulnerability, its impact, technical details, and mitigation strategies.

What is CVE-2021-3726?

The vulnerability lies in the

title

function within

ohmyzsh/ohmyzsh

, which can be exploited for OS command injection. While the function is used securely within Oh My Zsh, custom user code could misuse it, leading to potential security risks.

The Impact of CVE-2021-3726

With a CVSS base score of 7.5 (High), CVE-2021-3726 poses a significant threat to affected systems. It could allow attackers to execute arbitrary commands, compromising system confidentiality, integrity, and availability.

Technical Details of CVE-2021-3726

Let's delve deeper into the technical aspects of the vulnerability to understand how it operates and affects systems.

Vulnerability Description

The

title

function in

lib/termsupport.zsh

utilizes

print

to set the terminal title based on user input. However, custom user code could misuse this function to execute arbitrary commands, leading to OS command injection.

Affected Systems and Versions

The vulnerability impacts all versions of

ohmyzsh/ohmyzsh

prior to the fix implemented in version

a263cdac

.

Exploitation Mechanism

By creating a custom function that utilizes the

title

function with user-supplied strings, attackers can craft malicious commands to execute within the context of the terminal, bypassing security restrictions.

Mitigation and Prevention

Protecting your systems from CVE-2021-3726 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update Oh My Zsh to version

a263cdac

or later to mitigate the vulnerability.
Avoid executing custom or untrusted code that interacts with the

title

function.

Long-Term Security Practices

Regularly update and patch software to apply the latest security fixes.
Educate users on secure coding practices to prevent the introduction of vulnerable code.

Patching and Updates

Ensure that all systems running Oh My Zsh are regularly updated with the latest patches and security enhancements to mitigate the risks associated with CVE-2021-3726.