Buffer overflow in Siemens SIPROTEC 5 relays with CPU variants CP050
Priority LOW 35CWE-120Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-120 and the CVSS impact.
Summary
A vulnerability has been identified in SIPROTEC 5 relays with CPU variants CP050 (All versions < V8.80), SIPROTEC 5 relays with CPU variants CP100 (All versions < V8.80), SIPROTEC 5 relays with CPU variants CP300 (All versions < V8.80). Specially crafted packets sent to port 4443/tcp could cause a Denial-of-Service condition.
Why it matters now
EPSS 0.01037 64th percentileScored 2026-11-07
Fix Fixed SIPROTEC 5 relays with CPU variants CP050 (Siemens): V8.80SIPROTEC 5 relays with CPU variants CP100 (Siemens): V8.80+1 more product
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Siemens | SIPROTEC 5 relays with CPU variants CP050 | before V8.80 | V8.80 | Patch available | CNA |
| Siemens | SIPROTEC 5 relays with CPU variants CP100 | before V8.80 | V8.80 | Patch available | CNA |
| Siemens | SIPROTEC 5 relays with CPU variants CP300 | before V8.80 | V8.80 | Patch available | CNA |
- SIPROTEC 5 relays with CPU variants CP050 VendorSiemens Affected before V8.80 Fixed in V8.80 Patch available CNA
- SIPROTEC 5 relays with CPU variants CP100 VendorSiemens Affected before V8.80 Fixed in V8.80 Patch available CNA
- SIPROTEC 5 relays with CPU variants CP300 VendorSiemens Affected before V8.80 Fixed in V8.80 Patch available CNA
CPE configurations NVD · 3
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:siemens:siprotec_5_with_cpu_variant_cp050:*:*:*:*:*:*:*:* | before 8.80 | Vulnerable | Siemens |
| cpe:2.3:o:siemens:siprotec_5_with_cpu_variant_cp100:*:*:*:*:*:*:*:* | before 8.80 | Vulnerable | Siemens |
| cpe:2.3:o:siemens:siprotec_5_with_cpu_variant_cp300:*:*:*:*:*:*:*:* | before 8.80 | Vulnerable | Siemens |
- cpe:2.3:o:siemens:siprotec_5_with_cpu_variant_cp050:*:*:*:*:*:*:*:* Versions before 8.80 Vulnerable ·Siemens
- cpe:2.3:o:siemens:siprotec_5_with_cpu_variant_cp100:*:*:*:*:*:*:*:* Versions before 8.80 Vulnerable ·Siemens
- cpe:2.3:o:siemens:siprotec_5_with_cpu_variant_cp300:*:*:*:*:*:*:*:* Versions before 8.80 Vulnerable ·Siemens
Remediation
- Fix · CNA SIPROTEC 5 relays with CPU variants CP050 (Siemens) Fixed in V8.80
- Fix · CNA SIPROTEC 5 relays with CPU variants CP100 (Siemens) Fixed in V8.80
- Fix · CNA SIPROTEC 5 relays with CPU variants CP300 (Siemens) Fixed in V8.80
Timeline
- 2026-10-02 Threatist record created from CVE-2021-33720
- 2026-10-03 Alias added: GHSA-h98r-cwxp-2m8m
References
More Siemens Siprotec 5 With Cpu Variant Cp050 vulnerabilities
- TI-2021-13093 Buffer overflow in Siemens SIPROTEC 5 relays with CPU variants CP050 CVSS 3.1CRITICAL 9.8
- TI-2021-15268 Improper input validation in Siemens SIPROTEC 5 relays with CPU variants CP050 CVSS 3.1HIGH 7.5
Sources
- CVE-2021-33720 · CVE Program
- CVE-2021-33720 · NVD
- FIRST EPSS
- GHSA-h98r-cwxp-2m8m · GitHub Advisory Database · CC BY 4.0
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