Cyber Resilience

CVE-2021-33720

High

Published: 14 September 2021

Published
14 September 2021
Modified
21 November 2024
KEV Added
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Patch
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CVSS Score v3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0044 63.8th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-33720 is a high-severity Classic Buffer Overflow (CWE-120) vulnerability in Siemens Siprotec 5 With Cpu Variant Cp050. Its CVSS base score is 7.5 (High).

Operationally, ranked in the top 36.2% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

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…

more

crafted packets sent to port 4443/tcp could cause a Denial-of-Service condition.

CWE(s)
CWE-120

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

siemens
siprotec 5 with cpu variant cp050
≤ 8.80
siemens
siprotec 5 with cpu variant cp100
≤ 8.80
siemens
siprotec 5 with cpu variant cp300
≤ 8.80

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SC-27 Platform-independent Applications
addresses: CWE-120

Platform-independent managed code eliminates the need for unchecked native buffer copies that are the root cause of classic buffer overflows.

References