known ransomware use

SonicWall Email Security Improper Privilege Management Vulnerability

Added to KEV
2021-11-03
Federal due date
2021-11-17
Vendor
SonicWall
Product
SonicWall Email Security
EPSS
99.7th percentile (score 0.912, as of 2026-06-08)
NVD CVSS v3.1
Ransomware use
Known
Upstream
https://nvd.nist.gov/vuln/detail/CVE-2021-20021

CISA short description

SonicWall Email Security contains an improper privilege management vulnerability that allows an attacker to create an administrative account by sending a crafted HTTP request to the remote host. This vulnerability has known usage in a SonicWall Email Security exploit chain along with CVE-2021-20022 and CVE-2021-20023 to achieve privilege escalation.

Required action

Apply updates per vendor instructions.

EPSS percentile is the FIRST.org exploit-probability ranking as of the date noted above; it moves daily. CVSS reflects NVD's analysis at time of publication.