Netskope Security Advisory

NSKPSA-2021-002

Local privilege escalation vulnerability in Netskope Client on macOS

Security Advisory ID: NSKPSA-2021-002

Version: 1.0

Status: Published

Last Modified: December 20, 2021

Who should read this document	Technical and Security Personnel
Impact of Vulnerability	Privilege Escalation
CVE Number	CVE-2021-41388
Severity Rating	High
Overall CVSS Score	CVSS:3.1- 7.0 AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Recommendations	Install or update to the latest version released r89.x & above
Security Advisory Replacement	None
Caveats	None
Affected Software	Netskope Client on macOS v88 and earlier
Updated Software Version	Netskope Release 89 and later
Special Notes and Acknowledgements	Netskope would like to thank Red Team DART from The Home Depot for reporting the issue.
CWE Reference	CWE - CWE-269: Improper Privilege Management (4.5) CWE - CWE-250: Execution with Unnecessary Privileges (4.5)
Exploit Code Maturity (E)	Proof-of-Concept (P)
Remediation Level (RL)	Official Fix (O)
Report Confidence (RC)	Confirmed (C)

Description
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. Thus any low privileged user can connect and call external methods defined in XPC service as root, elevating their privilege to the highest level.

Affected Components: Netskope Client v88.x and earlier on macOS.

Remediation
Netskope has patched the issue and released a new version of Netskope client.
Customers are advised to upgrade the software to the latest version (89 or above).
Netskope macOS NSclient download Instructions can be found at Download Netskope Client and Scripts section – Netskope Support.

Workaround
No work around exists to mitigate the issue apart from upgrading to the latest version.

Special Notes and Acknowledgement
Netskope would like to thank Red Team DART from The Home Depot for reporting this vulnerability.

Support
Netskope Support Details.

FAQs

Do we use this for communication when a customer is abusing our systems?
No, please reach out to [email protected] for support on this.

What is affected by this security vulnerability?
Netskope Client v88.x and earlier on macOS.

Do I need to Update Immediately?
Netskope recommends that all customers run the latest version of software and evaluate this notification with other existing controls to make a determination. Netskope also recommends that customers leverage the CVSS v3.1 extended scoring or OWASP vulnerability criticality scoring tools to support his decision.

Affected Versions
88.x and earlier.

Protected Versions
89.x and later. Netskope recommends that all customers verify that they have applied the latest updates.

What issues do this release/patch address?
Please review the detailed changelog of the release.

How do I know if my Netskope Client on macOS is vulnerable or not?
To check the Netskope Client version on macOS, navigate to Netskope Client and then Right Click to see the option list. From the list select ‘About’, a pop up screen will display the used version.

What has Netskope done to resolve the issue?
Netskope has released a new version of the software to address this security flaw.

Where do I download the fix?
Please visit the release notes at https://support.netskope.com.

How does Netskope respond to this and any other security flaws
Netskope has a robust Cybersecurity program to address all security flaws in its products reported by external entities and found by internal assessment. The details of Netskope security program is listed at Security, Compliance and Assurance page.

How do I find out about security vulnerabilities with your products?
Please visit Security Advisories and Disclosures page.

How was this found?
This issue was reported by Red Team DART from The Home Depot.

Resources:
Support Website: https://www.netskope.com/services#support

Contacts: [email protected], [email protected]