CVE-2020-12494

mediumpriority · track · 20EPSS 0.010 · 63 %ileDEEURUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
1.01% (63rd) EPSS
CVSS 5 · medium
Is it mine?
30 products
Check your exposure
Who says so?
4 sources
cnnvd · enisa_euvd · fstec_bdu · beckhoff_psirt

EPSS · scored 2026-10-27

Beckhoff's TwinCAT RT network driver for Intel 8254x and 8255x is providing EtherCAT functionality. The driver implements real-time features. Except for Ethernet frames sent from real-time functionality, all other Ethernet frames sent through the driver are not padded if their payload is less than the minimum Ethernet frame size. Instead, arbitrary memory content is transmitted within in the padding bytes of the frame. Most likely this memory contains slices from previously transmitted or received frames. By this method, memory content is disclosed, however, an attacker can hardly control which memory content is affected. For example, the disclosure can be provoked with small sized ICMP echo requests sent to the device.

01

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

  • FixedTwinCAT 2.11 2350beckhoff_psirt

    Beckhoff offers software patches for TwinCAT 3.1 and TwinCAT 2.11 on request. These patches will be included in the the next regular releases to the affected software versions. The advisory will be updated upon availability.

  • FixedTwinCAT 3.1 402beckhoff_psirt

    Beckhoff offers software patches for TwinCAT 3.1 and TwinCAT 2.11 on request. These patches will be included in the the next regular releases to the affected software versions. The advisory will be updated upon availability.

  • FixedTwinCAT 3.1 4022beckhoff_psirt

    Beckhoff offers software patches for TwinCAT 3.1 and TwinCAT 2.11 on request. These patches will be included in the the next regular releases to the affected software versions. The advisory will be updated upon availability.

  • FixedTwinCAT 3.1 4024beckhoff_psirt

    Beckhoff offers software patches for TwinCAT 3.1 and TwinCAT 2.11 on request. These patches will be included in the the next regular releases to the affected software versions. The advisory will be updated upon availability.

  • MitigationTwinCAT 2.11 2350beckhoff_psirt

    If no real-time communication from TwinCAT is required on the Ethernet interface, then users can alternatively re-configure them to use the Intel ® driver, which is shipped with Beckhoff images. Customers should configure a perimeter firewall to block traffic from untrusted networks to the device, especially regarding ICMP and other small ethernet frames.

  • MitigationTwinCAT 3.1 402beckhoff_psirt

    If no real-time communication from TwinCAT is required on the Ethernet interface, then users can alternatively re-configure them to use the Intel ® driver, which is shipped with Beckhoff images. Customers should configure a perimeter firewall to block traffic from untrusted networks to the device, especially regarding ICMP and other small ethernet frames.

  • MitigationTwinCAT 3.1 4022beckhoff_psirt

    If no real-time communication from TwinCAT is required on the Ethernet interface, then users can alternatively re-configure them to use the Intel ® driver, which is shipped with Beckhoff images. Customers should configure a perimeter firewall to block traffic from untrusted networks to the device, especially regarding ICMP and other small ethernet frames.

  • MitigationTwinCAT 3.1 4024beckhoff_psirt

    If no real-time communication from TwinCAT is required on the Ethernet interface, then users can alternatively re-configure them to use the Intel ® driver, which is shipped with Beckhoff images. Customers should configure a perimeter firewall to block traffic from untrusted networks to the device, especially regarding ICMP and other small ethernet frames.

02

cvss

Technical severity, 0–10. One row per scoring source.

5.3
010

base score 0–10 · higher = more severe · hover a vector to decode

v2.05mediumAV:N/AC:L/Au:N/C:P/I:N/A:Nprimary · NVD / NIST USexploitability 10 · impact 2.9
v2.04.3mediumAV:N/AC:L/Au:N/C:P/I:N/A:N/E:Usecondary · CVSS-BT (t0sche)
v3.15.3mediumAV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:Nsecondary · FSTEC (BDU) RU
v3.15.3mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:Nsecondary · info@cert.vde.comexploitability 3.9 · impact 1.4
v3.15.3mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:Nsecondary · Beckhoff PSIRT DE
v3.15.3mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:Nsecondary · ENISA EU
v3.15.3mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:Nsecondary · NVD / NIST USexploitability 3.9 · impact 1.4
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-200USCWE-200USCWE-459USCWE-459US
04

affected products (30)

Products and version ranges known to be affected.

showing 20 of 30
05

advisories (1)

Vendor and ecosystem advisories describing this.

  • VDE-2020-019Beckhoff: EtherLeak in TwinCAT RT network driver2020-06-16csaf · beckhoff_psirtDE

    Beckhoff's TwinCAT RT network driver for Intel 8254x and 8255x is providing EtherCAT functionality. The driver implements real-time features. Except for Ethernet frames sent from real-time functionality, all other Ethernet frames sent through the driver are not padded if their payload is less than the minimum Ethernet frame size. Instead, arbitrary memory content is transmitted within in the padding bytes of the frame. Most likely this memory contains slices from previously transmitted or received frames.

06

also known as (4)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

cnnvdenisa_euvdfstec_bdubeckhoff_psirtNVDCVE.orgMITRE
published 2020-06-16modified 2026-06-17
08

references (4)

External citations — patches, advisories, analysis.

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