Every exploited vulnerability / SonicWall
CVE-2021-20021 in SonicWall SonicWall Email Security: known exploited
Generated from its entry in CISA's catalogue of known exploited vulnerabilities as of 3 November 2026.
Attackers are exploiting CVE-2021-20021 in SonicWall SonicWall Email Security. CISA has listed it as known exploited since 3 November 2021.
Ransomware groups have used this vulnerability.
| Product | SonicWall SonicWall Email Security |
|---|---|
| Known exploited since | 3 November 2021 |
| Ransomware use | Recorded |
| EU vulnerability database | EUVD-2021-7484 |
| Sources | NVD · CISA KEV |
What it means
Attackers have used this vulnerability in real attacks. An unpatched SonicWall SonicWall Email Security that can be reached from the internet is exposed to them.
What to do
- Apply the vendor's fix to every system running SonicWall SonicWall Email Security, starting with those reachable from the internet. Take a system off the internet until it can be fixed.
- Check the system for signs that it was reached before the fix.
How Vardion finds it
Wherever a scan or your imported scanner results find CVE-2021-20021, Vardion names the systems affected and puts the fix at the top of the list.