CVE-2021-23021

Local configuration disclosure via world-readable permissions

Published Jun 1, 2021 · Updated Aug 3, 2024

Incorrect permissions in the NGINX Controller agent in 3.x before 3.7.0 allow local users to read its configuration file. The agent assigns mode 0644 to /etc/controller-agent/agent.conf, granting every local account read access instead of restricting it to the service owner. A low-privileged account on the agent host is required, and exposure is limited to information stored in that file.

CVSS severity5.5
Medium
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect permissions in the NGINX Controller agent in 3.x before 3.7.0 allow local users to read its configuration file. The agent assigns mode 0644 to /etc/controller-agent/agent.conf, granting every local account read access instead of restricting it to the service owner. A low-privileged account on the agent host is required, and exposure is limited to information stored in that file.

The record

CVE
CVE-2021-23021
Published
Jun 1, 2021
Updated
Aug 3, 2024
Vendor
F5 Networks
Product
NGINX Controller
Classifications
CWE-732, T1005
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 1, 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=“3.x before 3.7.0”

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

F5 Networks · NGINX Controllerversion=“3.x before 3.7.0”

Published CVSS scores

2.1NIST NVDAV:L/AC:L/Au:N/C:P/I:N/A:N
5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

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.

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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

CWE-732Incorrect Permission Assignment for Critical Resource
T1005Data from Local System

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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