CVE-2023-28802
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedAn 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceImproper validation of integrity check value in Zscaler Client Connector for Windows allows an authenticated local user to bypass security controls and disable ZIA/ZPA services by interrupting the service restart process initiated through Zscaler Diagnostics. This enables a privileged user to circumvent security enforcement mechanisms.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 4.2.0.149CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- Low
- Availability
- Low
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check Zscaler Client Connector versionOpen Windows Registry Editor and navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Zscaler\ClientConnector (or HKEY_CURRENT_USER\SOFTWARE\Zscaler\ClientConnector). Look for a value named 'Version' or 'ClientConnectorVersion' to identify the installed build number.Affected if The installed version is lower than 4.2.0.149 (for example, 4.1.x.x or earlier). Compare the numeric version to the affected range.
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Verify Zscaler service statusOpen Services.msc and locate the 'Zscaler Client Connector' service (may be named 'Zscaler' or 'ZSClient'). Check if the service is running and note its current state.Affected if The service exists but is stopped, disabled, or in a non-functional state when it should be active.
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Check for Zscaler Diagnostics accessLocate the Zscaler Diagnostics tool on the system (typically in Program Files\Zscaler\ or ProgramData\Zscaler\ClientConnector\). Verify if the executable exists and can be invoked by a local authenticated user.Affected if The Zscaler Diagnostics executable is present and accessible to non-admin users, allowing them to initiate service restart operations.
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Inspect service configurationRun 'sc qc ZscalerClientConnector' (or the appropriate service name) from an elevated command prompt to examine the service binary path and startup type configuration.Affected if The service configuration shows unexpected binary paths or the service has been modified from its original installation state.
The environment is affected if the installed Zscaler Client Connector version is below 4.2.0.149 and the Zscaler Diagnostics feature is accessible to authenticated local users who could interrupt the service restart process.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped4.2.0.149
Upgrade Zscaler Client Connector to version 4.2.0.149 or later which implements proper integrity check validation to prevent unauthorized service modification.
Client Connector 4.2.0.149 or later
- Verify current Zscaler Client Connector version by checking the application or Windows Programs and Features
- Download Zscaler Client Connector version 4.2.0.149 or later from the official Zscaler portal or help.zscaler.com
- Run the installer with administrative privileges
- Follow the on-screen prompts to complete the upgrade
- Restart the system if prompted to ensure the update is fully applied
- Verify the installed version is 4.2.0.149 or later
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation4.0 h
- Testing4.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-28802 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2023-28802 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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