CVE-2020-5852Network attack vector

Traffic interruption via undisclosed FastL4 traffic patterns

Published Jan 14, 2020 · Updated Aug 4, 2024

Denial of service in F5 Networks BIG-IP engineering hotfixes allows remote attackers to restart TMM through a FastL4 virtual server. Public records do not identify the packet fields or TMM operation that mishandles the undisclosed traffic patterns. Exposure requires a FastL4 virtual server on Hotfix-BIGIP-14.1.2.1.0.83.4-ENG, Hotfix-BIGIP-12.1.4.1.0.97.6-ENG, or Hotfix-BIGIP-11.5.4.2.74.291-HF2; traffic processing stops during the restart.

CVSS severity7.5
High
EPSS probability1.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in F5 Networks BIG-IP engineering hotfixes allows remote attackers to restart TMM through a FastL4 virtual server. Public records do not identify the packet fields or TMM operation that mishandles the undisclosed traffic patterns. Exposure requires a FastL4 virtual server on Hotfix-BIGIP-14.1.2.1.0.83.4-ENG, Hotfix-BIGIP-12.1.4.1.0.97.6-ENG, or Hotfix-BIGIP-11.5.4.2.74.291-HF2; traffic processing stops during the restart.

The record

CVE
CVE-2020-5852
Published
Jan 14, 2020
Updated
Aug 4, 2024
Vendor
F5 Networks
Product
BIG-IP
Classifications
T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 14, 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=Hotfix-BIGIP-11.5.4.2.74.291-HF2
  2. Affected versionversion=Hotfix-BIGIP-12.1.4.1.0.97.6-ENG
  3. Affected versionversion=Hotfix-BIGIP-14.1.2.1.0.83.4-ENG

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

F5 Networks · BIG-IPversion=Hotfix-BIGIP-11.5.4.2.74.291-HF2; version=Hotfix-BIGIP-12.1.4.1.0.97.6-ENG; version=Hotfix-BIGIP-14.1.2.1.0.83.4-ENG

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

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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