Vulnerability

CVE-2021-20022

High· 7.2KEVCVSS7.2EPSS33%

.rules3/5

SonicWall Email Security Unrestricted Upload of File Vulnerability

SonicWall Email Security contains an unrestricted upload of file with dangerous type vulnerability that allows a post-authenticated attacker to upload a file to the remote host. This vulnerability has known usage in a SonicWall Email Security exploit chain along with CVE-2021-20021 and CVE-2021-20023 to achieve privilege escalation.

Threat signal

90/100

Severe

Severity

high

CVSS

7.2

EPSS

33%

Active

KEV

CISA KEV — actively exploited

Ransomware: Known1669d overdue

AffectedSonicWall — SonicWall Email Security

Added to KEV

2021-11-03

Federal patch due (BOD 22-01)

2021-11-17

Required action (CISA verbatim)

Apply updates per vendor instructions.

Vendor advisory + references

https://nvd.nist.gov/vuln/detail/CVE-2021-20022

CISA description: “SonicWall Email Security contains an unrestricted upload of file with dangerous type vulnerability that allows a post-authenticated attacker to upload a file to the remote host. This vulnerability has known usage in a SonicWall Email Security exploit chain along with CVE-2021-20021 and CVE-2021-20023 to achieve privilege escalation.”

CVSS

v3.1Open in FIRST calculator →

7.2/ 10HIGHCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

Attack VectorNetworkExploitable remotely over the internet — no local access needed.
Attack ComplexityLowNo special conditions — exploit works reliably.
Privileges RequiredHighAdmin / root privileges required.
User InteractionNoneFully automated — no victim action needed.
ScopeUnchangedImpact contained to the vulnerable component.
Confidentiality ImpactHighTotal disclosure of sensitive data.
Integrity ImpactHighTotal compromise of integrity — full data modification possible.
Availability ImpactHighTotal loss of availability — full DoS possible.

EPSS

Exploit prediction · 30-day horizonFIRST.org →

32.6%

probability of exploitation in next 30 days

p97

higher than 97% of all CVEs

3-day trend↑ 0pp

Above the FIRST 'patch on a priority schedule' threshold.

Vendor VEX

No VEX statements published for CVE-2021-20022. Vendors publish VEX (Vulnerability Exploitability eXchange) to assert per-product whether a CVE is actually exploitable in their distribution.

SSVCAct

Active exploitation with total impact on essential/support systems

exploitation: active
automatable: no
impact: total
mission: support

Lifecycle

2021-11-03Added to CISA KEVransomware: Known
2021-11-03Published
2021-11-17Federal patch due (BOD 22-01)
2026-06-12Last modified1 source

No source-event history recorded yet. New revisions will appear here as ingestors re-fetch this CVE.