Exploited Ransomware

CVE-2020-12271

Sophos Firewall (SFOS, ex-XG) · Firewalls, VPNs and remote access

Sophos SFOS SQL Injection Vulnerability

At a glance

Exploited. Added to CISA’s catalog of exploited vulnerabilities on November 3, 2021.

Used in ransomware attacks, according to CISA.

Affected product: Sophos Firewall (SFOS, ex-XG) (category Firewalls, VPNs and remote access, indicative classification). Name in CISA’s catalog: Sophos SFOS.

What should I do?

Apply the security update from Sophos.

Deadline set by CISA for US federal agencies: 181 days (due May 3, 2022). It only binds those agencies, but it is a useful measure of urgency.

Sophos security advisories page (general page, not the advisory for this vulnerability)
The vendor’s specific advisory is listed in the NVD references: CVE-2020-12271 on the NVD website.

Original text of the required action (CISA)

Apply updates per vendor instructions.

Timeline

April 27, 2020 Vulnerability published Publication date (NVD)
November 3, 2021 Exploitation confirmed Added to CISA’s KEV catalog
May 3, 2022 CISA deadline Remediation deadline set for US federal agencies

The facts, with their sources

Exploitation confirmed: Yes, on November 3, 2021 Date added to the catalog of exploited vulnerabilities. Exploitation itself may have started earlier. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
Ransomware: Known use Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
Hunt for compromise: Not requested by CISA Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
CISA required action: Apply the security update from Sophos. Rewritten by this site from CISA’s original text. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
CISA deadline: May 3, 2022, 181 days Set for US federal agencies: a measure of urgency, not an obligation elsewhere. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
Vulnerability published: April 27, 2020 Source: National Vulnerability Database (NVD), collected September 29, 2026 at 15:00 UTC
Product according to CISA: Sophos SFOS Filed by this site under “Firewalls, VPNs and remote access” (indicative classification). Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Technical detail of the score: attack vector, complexity, impact. Source: National Vulnerability Database (NVD), collected September 29, 2026 at 15:00 UTC

Severity and activity

9.8 / 10 CVSS severity: critical

Score from the NVD. Collected Sep 29, 2026.

— Probability of exploitation in the next 30 days (EPSS)

FIRST’s EPSS model. Since exploitation is already confirmed, this figure is mostly useful to compare activity. Collected Sep 29, 2026.

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)

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).

Summary from CISA (KEV catalog).

CERT-FR advisories

No advisory among the latest CERT-FR publications this site follows. That does not mean there are none.

Information reused under the Open Licence 2.0 (Etalab); the date of last update is shown for each advisory. This site is neither affiliated with nor endorsed by ANSSI.

Sources for this page

CISA KEV catalog: exploitation, date added, required action, deadline, ransomware.
NVD (NIST): CVSS severity, publication date, description, vendor references.
EPSS (FIRST): probability of exploitation.
CERT-FR: advisories and alerts (in French).
Brand and category: indicative classification by this site (method).