CVE-2021-20023

MEDIUMNVD 4.99.0▲Trending — 4 sources updated this weekExploited in the wild

4.9

SonicWall Email Security version 10.0.9.x contains a vulnerability that allows a post-authenticated attacker to read an arbitrary file on the remote host.

CVSS v3: 4.9
EG Score: 9.0(high)
EPSS: 98.1%
KEV: ⚠ Exploited

Published

April 20, 2021

Last Modified

November 12, 2025

References (3)

PSIRT@sonicwallhttps://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0010
af854a3a-2127-422b-91ae-364da2661108https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0010
134c704f-9b21-4f2e-91b3-4a467353bcc0https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-20023

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

CWE-22Path Traversal

Data Freshness Timeline

(refreshed 20× in last 7d / 20× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-06-08 07:07 UTCEG score recompute
2026-06-08 07:07 UTCGHSA enrichment
2026-06-08 03:20 UTCEG score recompute
2026-06-08 03:20 UTCGHSA enrichment
2026-06-07 23:33 UTCEG score recompute
2026-06-07 23:33 UTCGHSA enrichment
2026-06-07 19:46 UTCEG score recompute
2026-06-07 19:46 UTCGHSA enrichment
2026-06-07 15:59 UTCEG score recompute
2026-06-07 15:59 UTCGHSA enrichment
2026-06-07 15:23 UTCepss_batch
2026-06-07 15:23 UTCepss_batch
2026-06-07 12:11 UTCEG score recompute
2026-06-07 12:11 UTCGHSA enrichment
2026-06-07 08:24 UTCEG score recompute
2026-06-07 08:24 UTCGHSA enrichment
2026-06-07 04:36 UTCEG score recompute
2026-06-07 04:36 UTCGHSA enrichment
2026-06-07 00:49 UTCEG score recompute
2026-06-07 00:49 UTCGHSA enrichment

Frequently asked(6)

What is CVE-2021-20023?

CVE-2021-20023 is a medium vulnerability published on April 20, 2021. SonicWall Email Security version 10.0.9.x contains a vulnerability that allows a post-authenticated attacker to read an arbitrary file on the remote host.

When was CVE-2021-20023 disclosed?

CVE-2021-20023 was first published in the National Vulnerability Database on April 20, 2021, with the most recent update on November 12, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2021-20023 actively exploited?

Yes. CISA added CVE-2021-20023 to the Known Exploited Vulnerabilities catalog on November 3, 2021, affecting SonicWall SonicWall Email Security. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.

What is the CVSS score of CVE-2021-20023?

CVE-2021-20023 has a CVSS v3 base score of 4.9 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0.

Which products are affected by CVE-2021-20023?

CVE-2021-20023 affects SonicWall SonicWall Email Security. The full affected-products list, including version ranges and fixed versions, is shown in the Affected Packages section of this page.

How do I remediate CVE-2021-20023?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-20023, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2021-20023

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CVE-2021-20023

📅 Published

🔄 Last Modified

🔗 References (3)

Weakness Classification(1)

Data Freshness Timeline

❓ Frequently asked(6)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2021-20023?

🔗 Related CVEs(same CWE)

Same CWE

Published

Last Modified

References (3)

Frequently asked(6)

Related CVEs(same CWE)