Client ConnectorApplication · Zscaler

CVE-2020-11634

HIGH · 7.8 CVSS v3.1 Published 2021-07-15
Fix available
A fix is available. Upgrade to 2.1.2.105 or later.
See remediation →
81/100
Remediation priority · High
No privileges

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 · unedited
The Zscaler Client Connector for Windows prior to 2.1.2.105 had a DLL hijacking vulnerability caused due to the configuration of OpenSSL. A local adversary may be able to execute arbitrary code in the SYSTEM context.

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 confidence

A DLL hijacking vulnerability in Zscaler Client Connector for Windows (versions prior to 2.1.2.105) stems from insecure OpenSSL configuration. A local authenticated attacker with the ability to place a malicious DLL in a directory from which the application loads libraries could escalate privileges to execute arbitrary code in SYSTEM context.

MitigationUpgrade Zscaler Client Connector to version 2.1.2.105 or later to remediate this vulnerability.

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
Client ConnectorApplication
Affected:< 2.1.2.105

CVSS 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
Local
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

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 checks

Work through these to decide whether this CVE applies to you.

  1. Locate Zscaler Client Connector installation directory
    Check for Zscaler Client Connector in the Windows Program Files folder, typically at C:\Program Files\Zscaler\ or C:\Program Files (x86)\Zscaler\, and confirm the ZscalerClientConnector.exe executable exists.
    Affected if The Zscaler Client Connector application is installed on the system.
  2. Find installed version via Windows Registry
    Open Registry Editor and navigate to HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\, search for a subkey containing 'Zscaler Client Connector' or 'Zscaler' and read the DisplayVersion value. Alternatively, right-click the ZscalerClientConnector.exe file, select Properties, and view the Details tab for the Version field.
    Affected if A version number is returned that is lower than 2.1.2.105 (for example, 2.1.0.0 or 2.0.x.x).
  3. Confirm version via command line
    Open Command Prompt and run: dir "C:\Program Files\Zscaler\Zscaler Client Connector\ZscalerClientConnector.exe" /s 2>nul, then run: wmic product where "name like 'Zscaler%'" get version,name
    Affected if The command returns a version number less than 2.1.2.105.
  4. Identify running processes and service context
    Open Task Manager, look for ZscalerClientConnector.exe in the Processes tab, right-click and select Properties to view the executable path. Check if the process is running under the SYSTEM account by running: tasklist /svc | findstr Zscaler
    Affected if The Zscaler Client Connector service or process is running, indicating the vulnerable software is active on the system.

Your environment is affected if Zscaler Client Connector is installed and the detected version is any version prior to 2.1.2.105, as this version range contains the insecure OpenSSL configuration that enables DLL hijacking.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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.

From vendor data
Upgrade available Upgrade to 2.1.2.105 or later
Fixed in 2.1.2.105
Interim mitigation

Upgrade Zscaler Client Connector to version 2.1.2.105 or later to remediate this vulnerability.

Fix this in Client Connector Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,120.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2020-11634 — 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 sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2020-11634 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • 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
  • No spam, self-promotion, credentials, or personal data