CVE-2020-11635

System-privilege code execution via unvalidated RPC clients

Published Feb 16, 2021 · Updated Aug 4, 2024

Improper access control in Zscaler Client Connector for Windows before 3.1.0 allows local users to execute code with system privileges. The client fails to sufficiently validate local RPC clients, permitting an unprivileged local process to invoke privileged operations. Exploitation requires local access and does not require user interaction; the consequence can include system-level code execution and other actions beyond the attacker's privileges.

CVSS severity7.8
High
EPSS probability0.44%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper access control in Zscaler Client Connector for Windows before 3.1.0 allows local users to execute code with system privileges. The client fails to sufficiently validate local RPC clients, permitting an unprivileged local process to invoke privileged operations. Exploitation requires local access and does not require user interaction; the consequence can include system-level code execution and other actions beyond the attacker's privileges.

The record

CVE
CVE-2020-11635
Published
Feb 16, 2021
Updated
Aug 4, 2024
Vendor
Zscaler
Product
Zscaler Client Connector
Classifications
T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 16, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 3.1.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Zscaler · Zscaler Client Connectorversion=< 3.1.0

Published CVSS scores

7.8NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.2NVDAV:L/AC:L/Au:N/C:C/I:C/A:C

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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