How severe is CVE-2020-15783?

CVE-2020-15783 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-2020-15783 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-2020-15783?

CVE-2020-15783 primarily affects Siemens Sinumerik 840d Sl Firmware. In total, 12 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-15783?

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-2020-15783 published?

CVE-2020-15783 was published on 2020-11-12 and last updated on 2026-06-17.

CVE-2020-15783

CVE-2020-15783 is a high-severity vulnerability in Siemens Sinumerik 840d Sl 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-400.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 7.8
EPSS exploit prediction: 2% (73rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-400
Affected product: Siemens Sinumerik 840d Sl Firmware
Published: 2020-11-12
Last modified: 2026-06-17

Description

A vulnerability has been identified in SIMATIC S7-300 CPU family (incl. related ET200 CPUs and SIPLUS variants) (All versions), SIMATIC TDC CPU555 (All versions), SINUMERIK 840D sl (All versions). Sending multiple specially crafted packets to the affected devices could cause a Denial-of-Service on port 102. A cold restart is required to recover the service.

Frequently asked questions

What is CVE-2020-15783?: A vulnerability has been identified in SIMATIC S7-300 CPU family (incl. related ET200 CPUs and SIPLUS variants) (All versions), SIMATIC TDC CPU555 (All versions), SINUMERIK 840D sl (All versions). Sending multiple specially crafted packets to the affected devices could cause a Denial-of-Service on port 102. A cold restart is required to recover the service.
How severe is CVE-2020-15783?: CVE-2020-15783 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-2020-15783 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-2020-15783?: CVE-2020-15783 primarily affects Siemens Sinumerik 840d Sl Firmware. In total, 12 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-15783?: 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-2020-15783 published?: CVE-2020-15783 was published on 2020-11-12 and last updated on 2026-06-17.

References

https://cert-portal.siemens.com/productcert/pdf/ssa-492828.pdf

Affected products (12)

cpe:2.3:o:siemens:sinumerik_840d_sl_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-300_cpu_312_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-300_cpu_314_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-300_cpu_315-2_dp_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-300_cpu_315-2_pn_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-300_cpu_317-2_pn_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-300_cpu_317-2_dp_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-300_cpu_315f-2_dp_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-300_cpu_315f-2_pn_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-300_cpu_317f-2_pn_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-300_cpu_317f-2_dp_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_tdc_cpu555_firmware:*:*:*:*:*:*:*:*

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