CVE-2021-20099

Administrator execution in agent host context

Published Jun 28, 2021 · Updated Aug 3, 2024

Local privilege escalation in Tenable Nessus Agent 8.2.4 and earlier for Windows allows local users to execute specific programs as the agent host. Tenable has not published the affected component or the operation that mishandles those Windows executables. Exploitation requires an authenticated local administrator and permits execution in the Nessus Agent host security context.

CVSS severity6.7
Medium
EPSS probability0.43%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Local privilege escalation in Tenable Nessus Agent 8.2.4 and earlier for Windows allows local users to execute specific programs as the agent host. Tenable has not published the affected component or the operation that mishandles those Windows executables. Exploitation requires an authenticated local administrator and permits execution in the Nessus Agent host security context.

The record

CVE
CVE-2021-20099
Published
Jun 28, 2021
Updated
Aug 3, 2024
Vendor
Tenable
Product
Nessus Agent
Classifications
T1068
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Jun 28, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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=Nessus Agent 8.2.4 and earlier

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Tenable · Nessus Agentversion=Nessus Agent 8.2.4 and earlier

Published CVSS scores

6.7NIST NVDCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
4.6NIST NVDAV:L/AC:L/Au:N/C:P/I:P/A:P

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
Privilegesadmin
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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