How severe is CVE-2020-28393?

CVE-2020-28393 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2020-28393 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (73rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-28393?

CVE-2020-28393 primarily affects Siemens Scalance Xm-400 Firmware. In total, 11 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-28393?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2020-28393 published?

CVE-2020-28393 was published on 2021-05-12 and last updated on 2026-06-17.

CVE-2020-28393

CVE-2020-28393 is a high-severity vulnerability in Siemens Scalance Xm-400 Firmware with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-682.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 7.1
EPSS exploit prediction: 2% (73rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-682
Affected product: Siemens Scalance Xm-400 Firmware
Published: 2021-05-12
Last modified: 2026-06-17

Description

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).

Frequently asked questions

What is CVE-2020-28393?: 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).
How severe is CVE-2020-28393?: CVE-2020-28393 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2020-28393 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (73rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-28393?: CVE-2020-28393 primarily affects Siemens Scalance Xm-400 Firmware. In total, 11 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-28393?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2020-28393 published?: CVE-2020-28393 was published on 2021-05-12 and last updated on 2026-06-17.

References

Affected products (11)

cpe:2.3:o:siemens:scalance_xm-400_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_xr524_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_xr526_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_xr528_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_xr552_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_xm416-4c_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_xm408-8c_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_xm408-4c_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_xm416-4c_l3_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_xm408-8c_l3_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_xm408-4c_l3_firmware:*:*:*:*:*:*:*:*

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