CVE-2023-1671 Sophos Web Appliance Command Injection Vulnerability
Sophos Web Appliance contains a command injection vulnerability in the warn-proceed handler that allows for remote code execution.
From the CISA KEV catalogue version 2026.11.06, with Cybergen analysis. Updated 6 Nov 2026.
Should You Worry?
- CISA confirmed exploitation in the wild and added it to the Known Exploited Vulnerabilities catalogue on 16 Nov 2023.
- Rated Critical severity (CVSS 9.8, scored by Vendor).
- It has been in the catalogue for 1,086 days. Systems still unpatched now have almost certainly been scanned for it.
What It Is
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 Versions
| Product | Versions |
|---|---|
| Sophos Sophos Web Appliance | unspecified to before 4.3.10.4 |
From the public CVE record, as supplied by the vendor. Always confirm against the vendor advisory.
What To Do Now
- 1
Find it
Search your asset inventory and external attack surface for Sophos Web Appliance. Include cloud images, appliances and anything a supplier runs for you.
Attack Surface Management - 2
Fix it
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Vulnerability Management - 3
Hunt for compromise
If an affected system was reachable before you patched, assume it may have been hit. Check logs, new accounts, web shells and outbound connections from the date of exposure.
Incident Response - 4
Prove it is fixed
Rescan or test the system after patching. Upgrades that fail silently and forgotten secondary instances are common.
Penetration Testing
The Compliance Clock
General guidance, not legal advice. Your obligations depend on your sector, scope and jurisdiction.
Not Sure If You Are Exposed?
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