CVE-2021-20023 — SonicWall Email Security version 10
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.
Published
2021-04-20T12:15:12.587
Last modified
2026-10-01T21:17:16.097
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N
CISA KEV — Actively Exploited
01What is this vulnerability?
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.
02Affected products
No structured affected-product list available — see references below for vendor advisories.
03Active exploitation status
Yes — actively exploited. Added to the CISA KEV catalog on 2021-11-03. Ransomware use: Known.
04Recommended remediation
- Patch to a fixed version listed in the vendor advisory (see references below).
- Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
- Hunt historical logs for exploitation indicators — see Detection signatures below.
05Technical details
For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.
06Detection signatures
Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:
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07Related CVEs
No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.
08Timeline
- Published: 2021-04-20T12:15:12.587
- Last modified: 2026-10-01T21:17:16.097
- Added to CISA KEV: 2021-11-03
09References
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