CVE-2020-5879Network attack vector

Backend traffic disclosure via missing TLS re-encryption

Published Apr 30, 2020 · Updated Aug 4, 2024

Cleartext transmission in F5 Networks BIG-IP Application Security Manager 11.6.1 through 11.6.5.1 allows remote attackers to read backend traffic. When a Server SSL profile is applied, the affected data-plane path fails to re-encrypt traffic before forwarding it to configured back-end servers. Exposure requires the vendor-described configurations and a position from which the unencrypted server-side connection can be observed; no integrity or availability impact is reported.

CVSS severity7.5
High
EPSS probability0.81%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cleartext transmission in F5 Networks BIG-IP Application Security Manager 11.6.1 through 11.6.5.1 allows remote attackers to read backend traffic. When a Server SSL profile is applied, the affected data-plane path fails to re-encrypt traffic before forwarding it to configured back-end servers. Exposure requires the vendor-described configurations and a position from which the unencrypted server-side connection can be observed; no integrity or availability impact is reported.

The record

CVE
CVE-2020-5879
Published
Apr 30, 2020
Updated
Aug 4, 2024
Vendor
F5 Networks
Product
BIG-IP Application Security Manager
Classifications
CWE-319, T1040
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 30, 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=11.6.1-11.6.5.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

F5 Networks · BIG-IP Application Security Managerversion=11.6.1-11.6.5.1

Published CVSS scores

4.3NIST NVDAV:N/AC:M/Au:N/C:P/I:N/A:N
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/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.

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

CWE-319Cleartext Transmission of Sensitive Information
T1040Network Sniffing

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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