CVE-2021-20021
Act now ● On CISA KEV — actively exploited used in ransomware
Actively exploited — on the CISA KEV list.
CVSS base
9.8
CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS — probability of exploitation (30 days)
83.4%
99.7th percentile
CISA KEV
Listed
Added 2021-11-03 · patch by 2021-11-17
Weakness / dates
CWE-269
Published 2021-04-09 · modified 2026-08-12
CVSS breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
| Attack Vector | N | Network |
| Attack Complexity | L | Low |
| Privileges Required | N | None |
| User Interaction | N | None |
| Scope | U | Unchanged |
| Confidentiality | H | High |
| Integrity | H | High |
| Availability | H | High |
Timeline
- 2021-04-09 — Published (NVD)
- 2021-11-03 — Added to CISA KEV (actively exploited)
- 2021-11-17 — CISA patch-by deadline
- 2026-08-12 — Last modified (NVD)
Description
A vulnerability in the SonicWall Email Security version 10.0.9.x allows an attacker to create an administrative account by sending a crafted HTTP request to the remote host.