CVE-2021-20023

SonicWall Email Security contains a path traversal vulnerability that allows a post-authenticated attacker to read files on the remote host. This…

Browse: All 2021 CVEs · All vendors

CVSS score: 4.9 Medium
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N
CISA KEV: Yes — actively exploited (added 2021-11-03, remediation due 2021-11-17)
Ransomware: Known ransomware campaign use
Weakness (CWE): CWE-22
Published: 2021-04-20
Last modified: 2026-08-12
NVD status: Analyzed

Description

SonicWall Email Security contains a path traversal vulnerability that allows a post-authenticated attacker to read files on the remote host. This vulnerability has known usage in a SonicWall Email Security exploit chain along with CVE-2021-20021 and CVE-2021-20022 to achieve privilege escalation.

Affected products

sonicwall email security
sonicwall email security appliance 9000 firmware
sonicwall email security appliance 3300 firmware
sonicwall email security appliance 4300 firmware
sonicwall email security appliance 8300 firmware
sonicwall email security appliance 5000 firmware
sonicwall email security appliance 7000 firmware
sonicwall email security appliance 5050 firmware
sonicwall email security appliance 7050 firmware
sonicwall email security virtual appliance
sonicwall hosted email security

Affected ranges per NVD CPE data; confirm exact versions in the vendor advisory.

Required action (CISA)

Apply updates per vendor instructions. Federal remediation deadline: 2021-11-17.

How to prioritize this

This vulnerability is on the CISA KEV list, meaning it is being actively exploited — treat it as urgent regardless of the raw CVSS number. Use the live CVE lookup for the latest NVD data, and the CVSS 3.1 calculator to model your own environmental score. For the actively exploited vulnerabilities that matter this week, read The Exploit HQ daily security brief.

References

FAQ

Is CVE-2021-20023 actively exploited?

Yes. CISA added CVE-2021-20023 to its Known Exploited Vulnerabilities (KEV) catalog on 2021-11-03, with a federal remediation deadline of 2021-11-17. A KEV listing means real-world exploitation is confirmed, so patching this should be prioritized above many higher-CVSS bugs that aren't being exploited.

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

CVE-2021-20023 has a CVSS base score of 4.9 (Medium). Its vector string is CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N.

Related vulnerabilities

Data source: NVD & CISA KEV. Shown as-is; nothing added. Last generated from NVD data — re-check the live tool for updates.