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Vulnerabilities

Vulnerability · CVE-2021-20021

SonicWall Email Security Improper Privilege Management Vulnerability

Published Apr 9, 2021 · catalog updated Aug 11, 2026 · SonicWall SonicWall Email Security

Patch now

CVE-2021-20021 is in the CISA known-exploited catalog, due Nov 17, 2021. Confirm SonicWall SonicWall Email Security against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Gaps on this record

  • No version range is stored. A customer cannot check an installed version against this record.
Severity
Critical9.8
Known exploitation
CISA KEV and VulnCheck KEV
EPSS
88.78%
Remediation
Remediation guidance
Affected products
cpe sonicwall/email security · cpe sonicwall/email security appliance 3300 firmware · cpe sonicwall/email security appliance 4300 firmware · cpe sonicwall/email security appliance 5000 firmware · cpe sonicwall/email security appliance 5050 firmware · cpe sonicwall/email security appliance 7000 firmware

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe sonicwall/email securityversion unspecified
  • cpe sonicwall/email security appliance 3300 firmwareversion unspecified
  • cpe sonicwall/email security appliance 4300 firmwareversion unspecified
  • cpe sonicwall/email security appliance 5000 firmwareversion unspecified
  • cpe sonicwall/email security appliance 5050 firmwareversion unspecified
  • cpe sonicwall/email security appliance 7000 firmwareversion unspecified
  • cpe sonicwall/email security appliance 7050 firmwareversion unspecified
  • cpe sonicwall/email security appliance 8300 firmwareversion unspecified
  • cpe sonicwall/email security appliance 9000 firmwareversion unspecified
  • cpe sonicwall/email security virtual applianceversion unspecified
  • vendor SonicWall SonicWall Email Securityversion unspecified

How to fix CVE-2021-20021

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

CVE-2021-20021 is in the CISA known-exploited catalog, due Nov 17, 2021. Confirm SonicWall SonicWall Email Security against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Which versions are affected?

Affected version ranges are not on this record. Apply updates per vendor instructions.

What should an analyst verify?

CWE-269: Improper Privilege Management; CWE-306: Missing Authentication for Critical Function. EPSS 88.78%. The CISA KEV listing is the exploitation evidence. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Apr 9, 2021 · Catalog

    Detected

    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.

  2. Nov 3, 2021 · CISA KEV

    Known exploited

    Apply updates per vendor instructions.

  3. Nov 17, 2021 · CISA KEV

    Remediation due

    Apply updates per vendor instructions.

  4. Aug 11, 2026 · Catalog

    Updated

    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.

Sources

  • CISA KEVConfirmed exploitationCVE-2021-20021

    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.

    cisa.gov
  • CVE.orgVulnerability recordCVE-2021-20021

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2021-20021

    30-day exploitation probability 88.8%

    first.org
  • NIST NVDVulnerability recordCVE-2021-20021

    A vulnerability in the SonicWall Email Security version 10.0.9.x allows an attacker to create an administrative account by sending a crafted HTTP request to the remote host.

    nvd.nist.gov
  • VulnCheck KEVConfirmed exploitationCVE-2021-20021

    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

    vulncheck.com

References

Freshness

Last verified in this catalog Oct 17, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.