CVE-2020-28393

highpriority · track · 31EPSS 0.016 · 76 %ileDEEUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

1.63% (76th) EPSS

CVSS 7.1 · high

Is it mine?

18 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · cisa_csaf_ot · nvd

EPSS · scored 2026-10-27

An unauthenticated remote attacker could create a permanent denial-of-service condition by sending specially crafted OSPF packets. Successful exploitation requires OSPF to be enabled on an affected device on the SCALANCE XM-400, XR-500 (All versions prior to v6.4).

remediations

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

A vendor fix is available.

FixedSCALANCE XM-400 familysiemens_psirt
Update to V6.4 or later version
https://support.industry.siemens.com/cs/ww/en/view/109796319/
FixedSCALANCE XR-500 familysiemens_psirt
Update to V6.4 or later version
https://support.industry.siemens.com/cs/ww/en/view/109796317/
FixedSCALANCE XM-400 familycisa_csaf_ot
Update to V6.4 or later version
https://support.industry.siemens.com/cs/ww/en/view/109796319/
FixedSCALANCE XR-500 familycisa_csaf_ot
Update to V6.4 or later version
https://support.industry.siemens.com/cs/ww/en/view/109796317/
MitigationSCALANCE XM-400 familysiemens_psirt
Disable OSPF in the layer 3 configuration menu (note that OSPF is disabled by default). The vulnerability is not exploitable, when OSPF is disabled.
MitigationSCALANCE XR-500 familysiemens_psirt
Disable OSPF in the layer 3 configuration menu (note that OSPF is disabled by default). The vulnerability is not exploitable, when OSPF is disabled.
MitigationSCALANCE XM-400 familycisa_csaf_ot
Disable OSPF in the layer 3 configuration menu (note that OSPF is disabled by default). The vulnerability is not exploitable, when OSPF is disabled.
MitigationSCALANCE XR-500 familycisa_csaf_ot
Disable OSPF in the layer 3 configuration menu (note that OSPF is disabled by default). The vulnerability is not exploitable, when OSPF is disabled.

cvss

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

7.5

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.9–7.5

v2.07.1highAV:N/AC:M/Au:N/C:N/I:N/A:Cprimary · NVD / NIST USexploitability 8.6 · impact 6.9

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 3.6

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:Csecondary · CISA US

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:Csecondary · Siemens ProductCERT DE

v3.16.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-682USCWE-682USCWE-682US

affected products (18)

Products and version ranges known to be affected.

SCALANCE XM-400 familyall versionscisa_csaf_otUS
SCALANCE XR-500 Familyall versionscisa_csaf_otUS
Siemens SCALANCE XM-400 family< V6.4cisa_csaf_otUS
Siemens SCALANCE XR-500 family< V6.4cisa_csaf_otUS
n/a SCALANCE XM-400, XR-500≤ All versions prior to v6.4enisa_euvdEU
siemens scalance xm-400 firmware< 6.4nvdUScpe:2.3:o:siemens:scalance_xm-400_firmware:*:*:*:*:*:*:*:*
siemens scalance xm408-4c firmware< 6.4nvdUScpe:2.3:o:siemens:scalance_xm408-4c_firmware:*:*:*:*:*:*:*:*
siemens scalance xm408-4c l3 firmware< 6.4nvdUScpe:2.3:o:siemens:scalance_xm408-4c_l3_firmware:*:*:*:*:*:*:*:*
siemens scalance xm408-8c firmware< 6.4nvdUScpe:2.3:o:siemens:scalance_xm408-8c_firmware:*:*:*:*:*:*:*:*
siemens scalance xm408-8c l3 firmware< 6.4nvdUScpe:2.3:o:siemens:scalance_xm408-8c_l3_firmware:*:*:*:*:*:*:*:*
siemens scalance xm416-4c firmware< 6.4nvdUScpe:2.3:o:siemens:scalance_xm416-4c_firmware:*:*:*:*:*:*:*:*
siemens scalance xm416-4c l3 firmware< 6.4nvdUScpe:2.3:o:siemens:scalance_xm416-4c_l3_firmware:*:*:*:*:*:*:*:*
siemens scalance xr524 firmware< 6.4nvdUScpe:2.3:o:siemens:scalance_xr524_firmware:*:*:*:*:*:*:*:*
siemens scalance xr526 firmware< 6.4nvdUScpe:2.3:o:siemens:scalance_xr526_firmware:*:*:*:*:*:*:*:*
siemens scalance xr528 firmware< 6.4nvdUScpe:2.3:o:siemens:scalance_xr528_firmware:*:*:*:*:*:*:*:*
siemens scalance xr552 firmware< 6.4nvdUScpe:2.3:o:siemens:scalance_xr552_firmware:*:*:*:*:*:*:*:*
Siemens SCALANCE XM-400 family< V6.4siemens_psirtDE
Siemens SCALANCE XR-500 family< V6.4siemens_psirtDE

advisories (2)

Vendor and ecosystem advisories describing this.

SSA-116379SSA-116379: Denial-of-Service Vulnerability in OSPF Packet Handling of SCALANCE XM-400 and XR-500 Devices2021-05-11csaf · siemens_psirtDE
SCALANCE XM-400 and XR-500 devices contain a vulnerability in the OSPF protocol implementation that could allow an unauthenticated remote attacker to create a permanent denial-of-service condition. Siemens has released updates for the affected products and recommends to update to the latest versions.
ICSA-21-131-10Siemens SCALANCE XM-400 and XR-500 Devices2021-05-11icsa · cisa_csaf_otUS
SCALANCE XM-400 and XR-500 devices contain a vulnerability in the OSPF protocol implementation that could allow an unauthenticated remote attacker to create a permanent denial-of-service condition. Siemens has released updates for the affected products and recommends to update to the latest versions.

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd cisa_csaf_ot nvd siemens_psirt NVD CVE.org MITRE

published 2021-05-12modified 2026-06-17

references (8)

External citations — patches, advisories, analysis.

scry

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