CVE-2020-5894Network attack vector

Session hijacking via persistent logged-out tokens

Published May 7, 2020 · Updated Aug 4, 2024

Session hijacking in F5 Networks NGINX Controller 3.0.0 through 3.3.0 allows remote attackers to reuse a logged-out user's session token. The webserver leaves the server-side token valid after logout instead of invalidating the associated session, so possession or discovery of that token restores access. A valid token from a user who has logged out is required; reuse grants that user's Controller session privileges without affecting service availability.

CVSS severity8.1
High
EPSS probability1.02%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Session hijacking in F5 Networks NGINX Controller 3.0.0 through 3.3.0 allows remote attackers to reuse a logged-out user's session token. The webserver leaves the server-side token valid after logout instead of invalidating the associated session, so possession or discovery of that token restores access. A valid token from a user who has logged out is required; reuse grants that user's Controller session privileges without affecting service availability.

The record

CVE
CVE-2020-5894
Published
May 7, 2020
Updated
Aug 4, 2024
Vendor
F5 Networks
Product
NGINX Controller
Classifications
CWE-384, T1550.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 7, 2020CVE 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=< 3.4.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

F5 Networks · NGINX Controllerversion=< 3.4.0

Published CVSS scores

8.1NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
5.8NIST National Vulnerability DatabaseAV:N/AC:M/Au:N/C:P/I:P/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.

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

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-384Session Fixation
T1550.004Use Alternate Authentication Material: Web Session Cookie

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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