How severe is CVE-2020-12271?

CVE-2020-12271 has a CVSS score of 9.8/10, rated CRITICAL. Immediate patching is strongly recommended.

Which products are affected by CVE-2020-12271?

CVE-2020-12271 affects the following products: sophos sfos.

How do I patch CVE-2020-12271?

No patch has shipped for CVE-2020-12271 yet — track the sophos sfos advisory for a fixed release and apply the workarounds below in the meantime.

How do I detect CVE-2020-12271 across my infrastructure?

Inventory every sophos sfos deployment and check each version against the affected-products list above.

How do I mitigate CVE-2020-12271 if there is no patch (or I can't update yet)?

Until you can upgrade, make sure every query built from user input uses parameterised statements or a prepared-statement API rather than string concatenation, and reduce the database account's privileges so an injected query cannot read or alter data beyond what the feature needs. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.

Is CVE-2020-12271 actively exploited in the wild?

Yes. There are 5 known exploit references for CVE-2020-12271, including 5 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2020-12271?

CVE-2020-12271 has an EPSS (Exploit Prediction Scoring System) score of 42.4%, placing it in the 99th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score warrants monitoring and prompt remediation.

Is CVE-2020-12271 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2020-12271 (Sophos SFOS SQL Injection Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2021-11-03. CISA required all US federal civilian agencies to remediate this vulnerability by 2022-05-03. The required action was: Apply updates per vendor instructions. This CVE has been used in known ransomware campaigns. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2020-12271?

CVE-2020-12271 is classified as SQL Injection (CWE-89). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

Which products and versions are affected by CVE-2020-12271?

CVE-2020-12271 affects sophos sfos (4 versions, e.g. 17.0, 17.1, 17.5…). Check the affected-products list on this page against your deployed version to confirm exposure.

When was CVE-2020-12271 published, and has it been updated?

CVE-2020-12271 was published on April 27, 2020 and was last updated on June 17, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

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CISA KEV · ACTIVELY EXPLOITED

CRITICAL severity

CVE-2020-12271 — SFOS

CRITICAL

CVE-2020-12271 is a critical-severity (CVSS 9.8) SQL Injection vulnerability in sophos sfos. It is in CISA's Known Exploited Vulnerabilities catalog (added 2021-11-03) and has been used in ransomware campaigns — treat it as actively exploited and patch now. No vendor fix is recorded yet; mitigation options are listed below.

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…

Published

Apr 27, 2020

Updated

Jun 17, 2026

Affected

1 product

Patched

See advisory

Exploits

5 known

Exploitation data as of Oct 22, 2026 · OSV.dev, NVD, CISA KEV, FIRST.org (EPSS)

Exploitation Status

Actively exploited in the wild

Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2021-11-03 — including use in ransomware campaigns. Federal agencies were required to remediate by 2022-05-03.
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-2020-12271.

EPSS Exploitation Probability

via FIRST.org ↗

42.4%probability of exploitation in next 30 days

High Risk0.00%

Lower risk than most CVEs99th percentile — riskier than 99% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2020-12271 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 395,249 CVEs with a current EPSS score, this one falls in the 10–50% band (highlighted). Counts from FIRST.org, log-scaled.

Description

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)

Affected Products

1 product · 4 configurations

sfossophos

4 versions

17.017.117.518.0

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.