CVE-2023-1671
CriticalExploitedPublic exploitA pre-auth command injection vulnerability in the warn-proceed handler of Sophos Web Appliance older than version 4.3.10.4 allows execution of arbitrary code.
Published Apr 4, 2023 · Updated Oct 21, 2025
Key Facts
Patch immediately- CVE-2023-1671 is a critical-severity vulnerability (CVSS 9.8 v3.1) affecting Web Appliance (Sophos).
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Oct 14, 2023. Public exploit code is available.
- EPSS estimates a 100% probability of exploitation in the next 30 days.
- Fixed versions are available, including Web Appliance 4.3.10.4.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
100%
Higher than 99.9% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2023-1671 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
A pre-auth command injection vulnerability in the warn-proceed handler of Sophos Web Appliance older than version 4.3.10.4 allows execution of arbitrary code.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Nov 16, 2023 | Dec 7, 2023 | Not reported |
| Industry KEV feed | Nov 16, 2023 | Dec 7, 2023 | Not reported |
| CIRCL KEV | Oct 14, 2023 | Dec 7, 2023 | Not reported |
| ENISA EUVD | Nov 16, 2023 | n/a | Not reported |
Required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Affected Products
2 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Web ApplianceSophos | >= unspecified | 4.3.10.4 |
Patched Releases
Web Appliance
4.3.10.4
Timeline
Publicly disclosed
Apr 4, 2023
Added to CIRCL KEV
Oct 14, 2023
Added to CISA KEV
Nov 16, 2023
Added to Industry KEV feed
Nov 16, 2023
Added to ENISA EUVD
Nov 16, 2023
Last updated
Oct 21, 2025
Weakness Type
- CWE-77 Improper Neutralization of Special Elements used in a Command ('Command Injection')
References
- advisoryhttps://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2020-36692
- advisoryhttps://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2022-4934
- advisoryhttps://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2023-1671
- advisoryhttps://www.sophos.com/en-us/security-advisories/sophos-sa-20230404-swa-rce
- advisoryUSOM advisory
FAQ
Common Questions.
A pre-auth command injection vulnerability in the warn-proceed handler of Sophos Web Appliance older than version 4.3.10.4 allows execution of arbitrary code.
Affected: Web Appliance (Sophos) versions >= unspecified. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Oct 14, 2023.
Yes. It was added on Nov 16, 2023 with a federal remediation due date of Dec 7, 2023.
Public exploit code is available.
Fixed versions are available, including Web Appliance 4.3.10.4.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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