CVE-2021-25663

Exploitation

Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.

SSVC decision

Not assessed by CISA

EPSS probability

1.88% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 79.3% of scored records. A rank, not a probability.

NVD base score

8.7 (CVSS v4.0), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

NVD analysis status

Modified. NVD last modified this record on 2026-06-17.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2021-04-22 20:42Z5 YR AGO

Last updated

2025-03-11 09:47Z1 YR AGO

Reserved

2021-01-21

Assigning CNA

siemens

Record state

PUBLISHED

Severity

High (CVSS 8.7)

CNA CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Weaknesses

• CWE-835Loop with Unreachable Exit Condition ('Infinite Loop')Base

Data version

5.1

Document digest

6c0edb07c4eff2495ea5ff70378a70b564d1e7cd94bbcf19e5537c3b12313821

• cert-portal.siemens.comhttps://cert-portal.siemens.com/productcert/pdf/ssa-248289.pdfx_refsource_MISC
• us-cert.cisa.govhttps://us-cert.cisa.gov/ics/advisories/icsa-21-103-05x_refsource_CONFIRM
• cert-portal.siemens.comhttps://cert-portal.siemens.com/productcert/html/ssa-248289.html