CVE-2021-26735 : What You Need to Know

Understanding CVE-2021-26735

This article provides an overview of CVE-2021-26735, a vulnerability found in Zscaler's Client Connector Installer and Uninstallers for Windows prior to version 3.6.

What is CVE-2021-26735?

The vulnerability in the Zscaler Client Connector Installer and Uninstallers for Windows before version 3.6 is due to an unquoted search path issue. This flaw could allow a local attacker to execute arbitrary code with SYSTEM privileges.

The Impact of CVE-2021-26735

The impact of CVE-2021-26735 is categorized as a privilege escalation (CAPEC-233). An attacker could potentially escalate their privileges and gain unauthorized access to sensitive system resources.

Technical Details of CVE-2021-26735

This section delves into the technical aspects of the vulnerability.

Vulnerability Description

The vulnerability arises from an unquoted search path in the Zscaler Client Connector Installer and Uninstallers for Windows versions prior to 3.6. This could be exploited by a local adversary to execute malicious code with elevated privileges.

Affected Systems and Versions

The Zscaler Client Connector Installer and Uninstallers for Windows versions less than 3.6 are impacted by this vulnerability.

Exploitation Mechanism

To exploit this vulnerability, an attacker needs local access to the system. By manipulating the unquoted search path, they can run arbitrary code with elevated privileges.

Mitigation and Prevention

Protecting systems from CVE-2021-26735 requires immediate action and ongoing security practices.

Immediate Steps to Take

Upgrade to Zscaler Client Connector version 3.6 or later to mitigate the vulnerability.
Monitor system logs for any suspicious activity indicating exploitation of the vulnerability.

Long-Term Security Practices

Implement the principle of least privilege to restrict user permissions and limit potential damage from privilege escalation attacks.
Regularly update and patch software to mitigate known vulnerabilities and reduce the attack surface.

Patching and Updates

Stay informed about security updates and patches released by Zscaler for the Client Connector to address vulnerabilities and enhance system security.