CVE-2023-43124Public exploit

Traffic interception via manipulated routing exceptions

Published Sep 27, 2023 · Updated Sep 23, 2024

Cleartext transmission in F5 BIG-IP Edge Client and F5 Access allows man-in-the-middle attackers to intercept traffic outside the VPN tunnel. The clients preserve local-network and VPN-server routing exceptions after tunnel establishment, while attacker-controlled addressing or DNS makes chosen destinations match those exclusions. Exploitation requires control of the local access network or an on-path position before connection; exposed plaintext can reveal sensitive traffic, while protected traffic still discloses destination addresses.

CVSS severity5.3
Medium
EPSS probability0.15%
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 BIG-IP Edge Client and F5 Access allows man-in-the-middle attackers to intercept traffic outside the VPN tunnel. The clients preserve local-network and VPN-server routing exceptions after tunnel establishment, while attacker-controlled addressing or DNS makes chosen destinations match those exclusions. Exploitation requires control of the local access network or an on-path position before connection; exposed plaintext can reveal sensitive traffic, while protected traffic still discloses destination addresses.

The record

CVE
CVE-2023-43124
Published
Sep 27, 2023
Updated
Sep 23, 2024
Vendor
F5 Networks
Product
F5 Access
Classifications
CWE-319, T1557
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 27, 2023CVE publishedPublication date reported by the CVE source.
  2. Sep 23, 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=3.0 <*

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

F5 Networks · F5 Accessversion=3.0 <*
F5 Networks · BIG-IP Edge Clientversion=7.2.3 <*

Published CVSS scores

5.3F5CVSS:3.1/AV:A/AC:H/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.

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No observations available

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

Weakness, pattern, technique

CWE-319Cleartext Transmission of Sensitive Information
T1557Adversary-in-the-Middle

Public exploit references

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Technologies

Your stack

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Your stack

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