CVE-2021-37205A vulnerability has been identified in SIMATIC Drive Controller family (All versions >= V2.9.2 < V2.9.4), SIMATIC ET 200SP Open Controller…
- 7.5HighCVSS base score
- 1.6%Exploitation in 30 daysEPSS · top 23% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
A vulnerability has been identified in SIMATIC Drive Controller family (All versions >= V2.9.2 < V2.9.4), SIMATIC ET 200SP Open Controller CPU 1515SP PC2 (incl. SIPLUS variants) (All versions >= V21.9 < V21.9.4), SIMATIC S7-1200 CPU family (incl. SIPLUS variants) (All versions >= V4.5.0 < V4.5.2), SIMATIC S7-1500 CPU family (incl. related ET200 CPUs and SIPLUS variants) (All versions >= V2.9.2 < V2.9.4), SIMATIC S7-1500 Software Controller (All versions >= V21.9 < V21.9.4), SIMATIC S7-PLCSIM Advanced (All versions >= V4.0 < V4.0 SP1), SIPLUS TIM 1531 IRC (All versions < V2.3.6), TIM 1531 IRC (All versions < V2.3.6). An unauthenticated attacker could cause a denial-of-service condition in a PLC when sending specially prepared packets over port 102/tcp. A restart of the affected device is needed to restore normal operations.
Timeline
ID reserved
By siemens
- 7 months later
· 7 months later
Published
- 3 years later
· 3 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| siemensCNA (assigner) | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C |
| NVDNVD · Modified | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 1.6% · top 23% of all CVEs (13 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Affected products
Siemens · SIMATIC Drive Controller family
- affected All versions >= V2.9.2 < V2.9.4
Siemens · SIMATIC ET 200SP Open Controller CPU 1515SP PC2 (incl. SIPLUS variants)
- affected All versions >= V21.9 < V21.9.4
Siemens · SIMATIC S7-1200 CPU family (incl. SIPLUS variants)
- affected All versions >= V4.5.0 < V4.5.2
Siemens · SIMATIC S7-1500 CPU family (incl. related ET200 CPUs and SIPLUS variants)
- affected All versions >= V2.9.2 < V2.9.4
Siemens · SIMATIC S7-1500 Software Controller
- affected All versions >= V21.9 < V21.9.4
Siemens · SIMATIC S7-PLCSIM Advanced
- affected All versions >= V4.0 < V4.0 SP1
- affected All versions < V2.3.6
- affected All versions < V2.3.6
References
References1
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2021-23779 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2021-37205)Record last updated .