CVE-2021-20021

Exploitation

Exploited in the wild. Listed in the CISA Known Exploited Vulnerabilities catalog on 2021-11-03. Federal remediation due 2021-11-17.

SSVC decision

• ExploitationactiveCISA reports credible evidence of active exploitation.
• AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
• Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

83.43% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 99.7% of scored records. A rank, not a probability.

NVD base score

9.8 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

NVD analysis status

Analyzed. NVD last modified this record on 2026-08-12.

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

2021-04-09 17:50Z5 YR AGO

Last updated

2026-08-12 03:55Z24 DAYS AGO

Reserved

2020-12-17

Assigning CNA

sonicwall

Record state

PUBLISHED

Severity

Critical (CVSS 9.8)

CNA CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Weaknesses

• CWE-269Improper Privilege ManagementClass

Data version

5.2

Document digest

03a4774ca6974d687ec7ee268b4c994ea5ed13935a0f9e20c6d0ff53a80d6e78

• psirt.global.sonicwall.comhttps://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0007x_refsource_CONFIRM
• www.cisa.govhttps://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-20021government-resource