CVE-2021-41388 : Security Advisory and Response

Netskope client prior to 89.x on macOS is impacted by a local privilege escalation vulnerability. The XPC implementation of nsAuxiliarySvc process does not perform validation on new connections before accepting the connection. This allows low privileged users to elevate their privilege to the highest level.

Understanding CVE-2021-41388

What is CVE-2021-41388?

CVE-2021-41388 is a local privilege escalation vulnerability affecting Netskope client versions prior to 89.x on macOS. It occurs due to inadequate validation on new connections in the XPC implementation of the nsAuxiliarySvc process.

The Impact of CVE-2021-41388

This vulnerability enables low privileged users to connect and execute external methods defined in the XPC service as root, thereby escalating their privileges to the highest level.

Technical Details of CVE-2021-41388

Vulnerability Description

Vulnerability Type: Local Privilege Escalation
Affected System: Netskope client prior to version 89.x on macOS
Vulnerability Details: Lack of validation on new connections allows unauthorized privilege escalation.

Affected Systems and Versions

Product: Not applicable
Vendor: Not applicable
Affected Versions: All versions prior to 89.x on macOS

Exploitation Mechanism

The vulnerability allows low privileged users to establish unauthorized connections and execute root-level commands via XPC service, leading to privilege escalation.

Mitigation and Prevention

Immediate Steps to Take

Update Netskope client to version 89.x or above.
Monitor and restrict user permissions to minimize the impact of potential exploitation.

Long-Term Security Practices

Implement principle of least privilege to restrict unnecessary access.
Regularly review and update security configurations to address emerging threats.

Patching and Updates

Regularly check for security advisories from Netskope and apply patches promptly to mitigate vulnerabilities.