CVE-2023-43125

VPN traffic leak via tunnel bypass

Published Sep 27, 2023 · Updated Sep 24, 2024

Tunnel bypass in F5 BIG-IP APM clients 7.2.3 and 3.0 allows remote attackers to leak IP traffic via adjacent-network ServerIP attacks. The client routing logic can bypass the VPN tunnel when DNS spoofing redirects a ServerIP connection, sending traffic to an arbitrary address outside the protected tunnel. Exploitation requires an adjacent attacker able to spoof DNS responses; confidentiality and integrity of traffic can be lost, while availability is unaffected.

CVSS severity8.2
High
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Tunnel bypass in F5 BIG-IP APM clients 7.2.3 and 3.0 allows remote attackers to leak IP traffic via adjacent-network ServerIP attacks. The client routing logic can bypass the VPN tunnel when DNS spoofing redirects a ServerIP connection, sending traffic to an arbitrary address outside the protected tunnel. Exploitation requires an adjacent attacker able to spoof DNS responses; confidentiality and integrity of traffic can be lost, while availability is unaffected.

The record

CVE
CVE-2023-43125
Published
Sep 27, 2023
Updated
Sep 24, 2024
Vendor
F5 Networks
Product
F5 Access
Classifications
CWE-319, T1040
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 27, 2023CVE publishedPublication date reported by the CVE source.
  2. Sep 24, 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?

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  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

6.8F5 SIRTCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
8.2NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/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)
Vectoradjacent
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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