CVE-2020-12523

Phoenix Contact mGuard Devices versions before 8.8.3: LAN ports get functional after reboot even if they are disabled in the device configuration

CRITICAL

9.1

CVSS Score

Published: December 17, 2020 at 10:43 PM UTC

Updated: June 17, 2026 at 02:51 AM UTC

21 products affected across 2 vendorsFl Mguard RS4004 Tx /dtx VPN FirmwareFl Mguard RS4004 Tx /dtx FirmwareTc Mguard RS4000 4G VPN Firmware

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Severity

CRITICAL9.1

Exploit prediction

EPSS 0.9%

Description

On Phoenix Contact mGuard Devices versions before 8.8.3 LAN ports get functional after reboot even if they are disabled in the device configuration. For mGuard devices with integrated switch on the LAN side, single switch ports can be disabled by device configuration. After a reboot these ports get functional independent from their configuration setting: Missing Initialization of Resource

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Fl Mguard RS4004 Tx /dtx Firmware · Phoenix Contact

95%

v < 8.8.3

Affected range stops below 8.8.3, so it looks safe — our inference, not a vendor statement

phoenixcontact-fl-mguard-rs4004-tx-dtx (same device)

Fl Mguard RS4004 Tx /dtx VPN Firmware · Phoenix Contact

95%

v < 8.8.3

Affected range stops below 8.8.3, so it looks safe — our inference, not a vendor statement

phoenixcontact-fl-mguard-rs4004-tx-dtx-vpn (same device)

Innominate Mguard RS4000 4TX /3g /tx VPN Firmware · Phoenix Contact

95%

v < 8.8.3

Affected range stops below 8.8.3, so it looks safe — our inference, not a vendor statement

phoenixcontact-innominate-mguard-rs4000-4tx-3g-tx-vpn (same device)

Innominate Mguard RS4000 4TX /tx Firmware · Phoenix Contact

95%

v < 8.8.3

Affected range stops below 8.8.3, so it looks safe — our inference, not a vendor statement

phoenixcontact-innominate-mguard-rs4000-4tx-tx (same device)

Innominate Mguard RS4000 4TX /tx VPN Firmware · Phoenix Contact

95%

v < 8.8.3

Affected range stops below 8.8.3, so it looks safe — our inference, not a vendor statement

phoenixcontact-innominate-mguard-rs4000-4tx-tx-vpn (same device)

Tc Mguard RS4000 3G VPN Firmware · Phoenix Contact

95%

All versions

phoenixcontact-tc-mguard-rs4000-3g-vpn (same device)

Tc Mguard RS4000 4G Att VPN Firmware · Phoenix Contact

95%

v < 8.8.3

Affected range stops below 8.8.3, so it looks safe — our inference, not a vendor statement

phoenixcontact-tc-mguard-rs4000-4g-att-vpn (same device)

Tc Mguard RS4000 4G VPN Firmware · Phoenix Contact

95%

v < 8.8.3

Affected range stops below 8.8.3, so it looks safe — our inference, not a vendor statement

phoenixcontact-tc-mguard-rs4000-4g-vpn (same device)

Tc Mguard RS4000 4G Vzw VPN Firmware · Phoenix Contact

95%

v < 8.8.3

Affected range stops below 8.8.3, so it looks safe — our inference, not a vendor statement

TC MGUARD RS4000 4G VZW VPN · Phoenix Contact

90%

v < 8.8.3

Affected range stops below 8.8.3, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (1)

x_refsource_CONFIRMThird Party Advisory

Source: [email protected]

https://cert.vde.com/en-us/advisories/vde-2020-046

CVSS

9.1CRITICAL[email protected]

Attack Vector: NETWORK
Complexity: LOW
Privileges: NONE
User Interaction: NONE
Scope: UNCHANGED
Confidentiality: HIGH
Integrity: NONE
Availability: HIGH

Vector?

Quick Info

StatusMODIFIED

CWE

CWE-909

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