SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2021-33720

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).

HIGH 7.5EPSS 1.04%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.04%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
1.04% probability · 62th percentile
CISA KEV
Not listed
Weakness
CWE-120
Affected
siemens/siprotec 5 with cpu variant cp050 · siemens/siprotec 5 with cpu variant cp100 · siemens/siprotec 5 with cpu variant cp300
Source
productcert@siemens.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.