CVE-2021-23020

Local API-key disclosure via predictable generation

Published Jun 1, 2021 · Updated Aug 3, 2024

Insufficiently random value generation in NGINX Controller 3.x before 3.10.0 allows local users to obtain predictable API keys. NAAS generates keys with an insecure pseudo-random string and hashing algorithm, making key values predictable. Local access is required, and the demonstrated consequence is disclosure of API credentials that can enable access permitted to those keys.

CVSS severity5.5
Medium
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Insufficiently random value generation in NGINX Controller 3.x before 3.10.0 allows local users to obtain predictable API keys. NAAS generates keys with an insecure pseudo-random string and hashing algorithm, making key values predictable. Local access is required, and the demonstrated consequence is disclosure of API credentials that can enable access permitted to those keys.

The record

CVE
CVE-2021-23020
Published
Jun 1, 2021
Updated
Aug 3, 2024
Vendor
F5 Networks
Product
NGINX Controller
Classifications
CWE-330, T1078
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 3.10.0”

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

F5 Networks · NGINX Controllerversion=“3.x before 3.10.0”

Published CVSS scores

5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
2.1NVDAV:L/AC:L/Au:N/C:P/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-330Use of Insufficiently Random Values
T1078Valid Accounts

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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