CVE-2023-28802: Disable Zscaler using machine tunnel restart

Severity: medium (CVSS 5.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2023-11-21 · updated 2026-06-17
Weakness: CWE-354

Description

An Improper Validation of Integrity Check Value in Zscaler Client Connector on Windows allows an authenticated user to disable ZIA/ZPA by interrupting the service restart from Zscaler Diagnostics. This issue affects Client Connector: before 4.2.0.149.

Affected products

Zscaler Client Connector: before 4.2.0.149 — fixed in 4.2.0.149

How to fix

Upgrade to a fixed version: Zscaler Client Connector 4.2.0.149. Check the vendor advisory for mitigations.

References

https://help.zscaler.com/client-connector/client-connector-app-release-summary-2023?applicable_category=Windows&applicable_version=4.2
https://help.zscaler.com/client-connector/client-connector-app-release-summary-2023?applicable_category=Windows&applicable_version=4.2

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