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CVE-2021-33720

HIGH
7.5
CVSS Score
Published: September 14, 2021 at 10:47 AM UTC
Updated: June 17, 2026 at 03:55 AM UTC
3 products affected across 1 vendorSiprotec 5 with CPU Variant CP100Siprotec 5 with CPU Variant CP300Siprotec 5 with CPU Variant CP050

Using SIPROTEC 5 relays with CPU variants CP050 by Siemens?

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Severity
HIGH7.5
Exploit prediction
EPSS 1%

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Siprotec 5 with CPU Variant CP050· Siemens
95%
v < 8.80All versions < V8.80
Affected range stops below 8.80, so it looks safe — our inference, not a vendor statement
Siprotec 5 with CPU Variant CP100· Siemens
95%
v < 8.80All versions < V8.80
Affected range stops below 8.80, so it looks safe — our inference, not a vendor statement
Siprotec 5 with CPU Variant CP300· Siemens
95%
v < 8.80All versions < V8.80
Affected range stops below 8.80, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

References (1)

x_refsource_MISCPatchVendor Advisory
Source: [email protected]
https://cert-portal.siemens.com/productcert/pdf/ssa-847986.pdf

CVSS

7.5HIGH[email protected]
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-120

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