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Actively exploitedKnown ransomware use

CVE-2020-12271 Sophos SFOS SQL Injection Vulnerability

Sophos Firewall operating system (SFOS) firmware contains a SQL injection vulnerability when configured with either the administration (HTTPS) service or the User Portal is exposed on the WAN zone. Successful exploitation may cause remote code execution to exfiltrate usernames and hashed passwords for the local device admin(s), portal admins, and user accounts used for remote access (but not external Active Directory or LDAP passwords).

From the CISA KEV catalogue version 2026.11.06, with Cybergen analysis. Updated 6 Nov 2026.

Our Assessment

Should You Worry?

Patch nowCybergen assessment
  • CISA confirmed exploitation in the wild and added it to the Known Exploited Vulnerabilities catalogue on 3 Nov 2021.
  • CISA lists it as known to be used in ransomware campaigns.
  • Rated Critical severity (CVSS 10.0, scored by Vendor).
  • It has been in the catalogue for 1,829 days. Systems still unpatched now have almost certainly been scanned for it.
The Vulnerability

What It Is

A SQL injection issue was found in SFOS 17.0, 17.1, 17.5, and 18.0 before 2020-04-25 on Sophos XG Firewall devices, as exploited in the wild in April 2020. This affected devices configured with either the administration (HTTPS) service or the User Portal exposed on the WAN zone. A successful attack may have caused remote code execution that exfiltrated usernames and hashed passwords for the local device admin(s), portal admins, and user accounts used for remote access (but not external Active Directory or LDAP passwords)

From Watch to Action

What To Do Now

  1. 1

    Find it

    Search your asset inventory and external attack surface for Sophos SFOS. Include cloud images, appliances and anything a supplier runs for you.

    Attack Surface Management
  2. 2

    Fix it

    Apply updates per vendor instructions.

    Vulnerability Management
  3. 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. 4

    Prove it is fixed

    Rescan or test the system after patching. Upgrades that fail silently and forgotten secondary instances are common.

    Penetration Testing

Vendor Advisories

Regulation

The Compliance Clock

Cyber EssentialsRated critical, so if it affects devices in your Cyber Essentials scope, the update must be installed within 14 days of the vendor releasing it.NIS2If exploitation causes a significant incident, essential and important entities owe their CSIRT an early warning within 24 hours and a notification within 72 hours.DORAFinancial entities must classify ICT incidents and send an initial notification for a major incident within strict deadlines, with exploited flaws a common cause.US federal (BOD 22-01)Federal civilian agencies had until 3 May 2022 to remediate. A sensible benchmark for everyone else.

General guidance, not legal advice. Your obligations depend on your sector, scope and jurisdiction.

Stay Ahead

More Exploited Sophos Flaws

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CVE-2020-15069Sophos XG Firewall Buffer Overflow VulnerabilityAdded 6 Feb 2025CVE-2020-29574 · RansomwareCyberoamOS (CROS) SQL Injection VulnerabilityAdded 6 Feb 2025CVE-2023-1671Sophos Web Appliance Command Injection VulnerabilityAdded 16 Nov 2023CVE-2022-3236Sophos Firewall Code Injection VulnerabilityAdded 23 Sep 2022CVE-2022-1040Sophos Firewall Authentication Bypass VulnerabilityAdded 31 Mar 2022CVE-2020-25223Sophos SG UTM Remote Code Execution VulnerabilityAdded 25 Mar 2022

All 7 exploited Sophos vulnerabilities

Not Sure If You Are Exposed?

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Evidence

Sources

  1. CISA Known Exploited Vulnerabilities catalogue
  2. NVD: CVE-2020-12271
  3. CVE record: CVE-2020-12271
  4. FIRST EPSS
  5. cwe.mitre.org/data/definitions/89.html
  6. community.sophos.com/kb/en-us/135412
  7. news.sophos.com/en-us/2020/04/26/asnarok/