IRONSMITHINTEL
CRITICALCVSS9.8
|
Actively Exploited
|CISA KEV|CVE-2023-1671|Auth: none — unauthenticated|Reboot: required|Manual only

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.

Published Apr 4, 2023 · Updated May 16, 2026
Why patchRisk explained in plain English
Worst-case scenarioIf unpatched

A remote attacker, without authentication, can achieve full data confidentiality loss, arbitrary modification of data, complete denial of service or system unavailability. Federal agencies are required to remediate by 2023-12-07 under CISA BOD 22-01.

How the attack worksNo clicks needed

This is a Command Injection (CWE-77) vulnerability in Sophos Web Appliance. 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. Exploitation requires remote network access, low attack complexity, no authentication required, and no user interaction required.

📧

Phishing link

🖼

Malicious file

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Server compromised

Am I affected?Quick check

Probably yes if any of these apply:

IT Security
Running web appliance: v < 4.3.10.4
Real-world incidentsWhat we've seen

Active exploitation documented in the wild. Threat-research write-up: http://packetstormsecurity.com/files/172016/Sophos-Web-Appliance-4.3.10.4-Command-Injection.html

How to patch

Manual remediation steps

Apply the Vendor Patch

This vulnerability is in the CISA Known Exploited Vulnerabilities catalog — apply the vendor's security update as soon as possible.

CISA required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

References

    1
    Vendor advisory: https://www.sophos.com/en-us/security-advisories/sophos-sa-20230404-swa-rce
    1
    NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2023-1671
    1
    CISA KEV: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-1671
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