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CVE-2021-26737

Privilege Escalation Using PID Reuse in ZCC macOS

MEDIUM
4.7
CVSS Score
Published: October 23, 2023 at 01:22 PM UTC
Updated: June 17, 2026 at 03:43 AM UTC
1 product affected across 1 vendorClient Connector

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Severity
MEDIUM4.7
Exploit prediction
EPSS 0.1%
SSVC
No known exploit

Description

The Zscaler Client Connector for macOS prior to 3.6 did not sufficiently validate RPC clients. A local adversary without sufficient privileges may be able to shutdown the Zscaler tunnel by exploiting a race condition.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Client Connector· Zscaler
95%
v < 3.6
Affected range stops below 3.6, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (1)

Release Notes
Source: [email protected]
https://help.zscaler.com/client-connector/client-connector-app-release-summary-2022?applicable_category=macOS&applicable_version=3.6&deployment_date=2022-01-07&id=1388686

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

4.7MEDIUM[email protected]
Attack Vector
LOCAL
Complexity
HIGH
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-346

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