CVE-2023-1671
CRITICALCVE-2023-1671 is a critical-severity (CVSS 9.8) CWE-77 vulnerability. It is in CISA's Known Exploited Vulnerabilities catalog (added 2023-11-16) — treat it as actively exploited and patch now. No vendor fix is recorded yet; mitigation options are listed below.
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 Status
Actively exploited in the wild
- Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2023-11-16. Federal agencies were required to remediate by 2023-12-07.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2023-1671.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2023-1671 by exploitation likelihood (EPSS) against impact (CVSS). In the shaded patch-first corner (EPSS 50%+, CVSS 7.0+).
Where this sits among everything scored
Of 394,415 CVEs with a current EPSS score, this one falls in the ≥ 90% band (highlighted). Counts from FIRST.org, log-scaled.
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.
Affected Products
web appliancesophosResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Sophos Web Appliance 4.3.10.4 - Pre-auth command injection
by Behnam Abasi Vanda · Apr 25, 2023
Detection & mitigation playbook
VulnerabilityDetect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Remediation status
No fixed release is recorded for CVE-2023-1671 yet. Track the upstream advisory, and apply the exposure-reduction steps below in the meantime.
Mitigate without a patch
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.
How to detect CVE-2023-1671
A community-maintained Nuclei template exists for this CVE. You can scan for it directly:
nuclei -id cve-2023-1671 -u https://target- Template
- Sophos Web Appliance - Remote Code Execution
- Severity
- critical
- Impact
- Successful exploitation of this vulnerability could allow an attacker to execute arbitrary code on the affected system.
- Remediation
- Apply the latest security patches or updates provided by Sophos to mitigate this vulnerability.
Template by ProjectDiscovery nuclei-templates (Co5mos), MIT licensed. View the full template. Scan only systems you are authorised to test.
Frequently Asked Questions
Is CVE-2023-1671 in your dependencies?
Find it across , including transitive dependencies.