CVE-2022-1040 — SFOS
CRITICALCVE-2022-1040 is a critical-severity (CVSS 9.8) vulnerability in sophos sfos. It is in CISA's Known Exploited Vulnerabilities catalog (added 2022-03-31) — treat it as actively exploited and patch now. No vendor fix is recorded yet; mitigation options are listed below.
An authentication bypass vulnerability in the User Portal and Webadmin allows a remote attacker to execute code in Sophos Firewall version v18.5 MR3 and older.
Exploitation Status
Actively exploited in the wild
- Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2022-03-31. Federal agencies were required to remediate by 2022-04-21.
- 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-2022-1040.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2022-1040 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 394,803 CVEs with a current EPSS score, this one falls in the ≥ 90% band (highlighted). Counts from FIRST.org, log-scaled.
Description
An authentication bypass vulnerability in the User Portal and Webadmin allows a remote attacker to execute code in Sophos Firewall version v18.5 MR3 and older.
Affected Products
sfossophosResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Sophos XG115w Firewall 17.0.10 MR-10 - Authentication Bypass
by Aryan Chehreghani · Sep 2, 2022
Detection & mitigation playbook
Vendor / applianceDetect
Inventory every sophos sfos deployment and check each version against the affected-products list above.
Remediation status
No patch has shipped for CVE-2022-1040 yet — track the sophos sfos advisory for a fixed release and apply the workarounds below in the meantime.
Mitigate without a patch
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.
How to detect CVE-2022-1040
A community-maintained Nuclei template exists for this CVE. You can scan for it directly:
nuclei -id cve-2022-1040 -u https://target- Template
- Sophos Firewall <=18.5 MR3 - Remote Code Execution
- Severity
- critical
- Impact
- Successful exploitation of this vulnerability could allow an attacker to execute arbitrary code on the affected system, potentially leading to complete compromise of the firewall.
- Remediation
- Upgrade to a patched version of Sophos Firewall (>=18.5 MR4) to mitigate this vulnerability.
Template by ProjectDiscovery nuclei-templates (For3stCo1d), MIT licensed. View the full template. Scan only systems you are authorised to test.
Frequently Asked Questions
Is CVE-2022-1040 being exploited in your environment?
Detect and block the exploit chain at execution, on systems you cannot patch yet.