CVE-2021-20021Actively exploitedAdded to KEV 2021-11-03Known ransomware campaign use

SonicWall Email Security Improper Privilege Management Vulnerability

SonicWall, SonicWall Email Security

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.

CVSS severity for this advisory hasn't been enriched from NVD yet, check back shortly.

EPSS, exploit probability

Critical

88.8%

estimated chance of real-world exploitation in the next 30 days, higher than 99.8% of every CVE FIRST.org scores

Refreshed 10/28/2026, via FIRST.org's EPSS model, not CVSS, this measures likelihood of exploitation, not how severe it would be.

Required action

Apply updates per vendor instructions.

CISA-recommended due date: 2021-11-17

CWE-306

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