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?

Affected package information for CVE-2020-12271 is not yet fully mapped. Check the official advisory links for details.

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. Because the exploit targets the running system rather than your application code, also watch for remote code execution at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.

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

Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.

How does O3 Security protect against CVE-2020-12271?

O3 detects and blocks CVE-2020-12271 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.

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 42.2%, 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.

CISA KEV·Added 2021-11-03 — agencies required to remediate by 2022-05-03 · Ransomware

CVE-2020-12271

CRITICAL

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

0 pkgs

Patched

None yet

Exploits

5 known

EPSS Exploitation Probability

via FIRST.org ↗

42.2%probability of exploitation in next 30 days

High Risk99th percentile-0.90%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

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.