Known exploited · SonicWall
CVE-2021-20021: SonicWall Email Security Improper Privilege Management Vulnerability
What it is
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.
- Vendor
- SonicWall
- Product
- SonicWall Email Security
- Added to KEV
- November 3, 2021
- CISA due date
- November 17, 2021
- Ransomware use
- Known
What CISA requires
Apply updates per vendor instructions.
Forensic triage
No
What to do now
- Find every instance of SonicWall Email Security you run, including the forgotten ones, and check its version against the vendor advisory.
- Apply the vendor's fix or mitigation, before November 17, 2021 if you are bound by CISA's deadline, sooner if it faces the internet.
- Assume it was tried against you already: look for signs of exploitation from the date it was added, not from the day you patched.
References
H2 Security
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Start freeSource: CISA Known Exploited Vulnerabilities Catalog (public domain), catalog version 2026.10.01.