CVE-2021-42711 Explained : Impact and Mitigation

Barracuda Network Access Client before 5.2.2 creates a Temporary File in a Directory with Insecure Permissions. This file is executed with SYSTEM privileges when an unprivileged user performs a repair operation.

Understanding CVE-2021-42711

Barracuda Network Access Client vulnerability

What is CVE-2021-42711?

This CVE refers to a security issue in Barracuda Network Access Client where a Temporary File is created in a Directory with Insecure Permissions, leading to its execution with SYSTEM privileges during a repair operation by an unprivileged user.

The Impact of CVE-2021-42711

Unauthorized users can exploit the vulnerability to gain SYSTEM privileges
Malicious files can be executed with elevated permissions

Technical Details of CVE-2021-42711

Details of the vulnerability

Vulnerability Description

The vulnerability arises from the creation of a Temporary File with inadequate directory permissions, allowing its execution with SYSTEM privileges during a repair operation.

Affected Systems and Versions

Product: Barracuda Network Access Client
Affected Version: < 5.2.2

Exploitation Mechanism

The vulnerability is exploited when an unprivileged user initiates a repair operation, triggering the execution of the malicious Temporary File with elevated SYSTEM privileges.

Mitigation and Prevention

Steps to address the CVE-2021-42711

Immediate Steps to Take

Update Barracuda Network Access Client to version 5.2.2 or newer
Restrict access to vulnerable systems
Monitor and analyze system activities for unusual behavior

Long-Term Security Practices

Regularly audit file system permissions
Implement the principle of least privilege to restrict user capabilities
Educate users on security best practices

Patching and Updates

Apply vendor-provided patches promptly
Maintain up-to-date security solutions