Exploited

CVE-2022-1040

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

Sophos Firewall Authentication Bypass Vulnerability

At a glance

Exploited. Added to CISA’s catalog of exploited vulnerabilities on March 31, 2022.

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

What should I do?

Apply the security update from Sophos.

Deadline set by CISA for US federal agencies: 21 days (due April 21, 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-2022-1040 on the NVD website.

Original text of the required action (CISA)

Apply updates per vendor instructions.

Timeline

March 25, 2022 Vulnerability published Publication date (NVD)
March 31, 2022 Exploitation confirmed Added to CISA’s KEV catalog
April 21, 2022 CISA deadline Remediation deadline set for US federal agencies

The facts, with their sources

Exploitation confirmed: Yes, on March 31, 2022 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: No known use to date That does not guarantee it is not being used: the information is not public. 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: April 21, 2022, 21 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: March 25, 2022 Source: National Vulnerability Database (NVD), collected September 29, 2026 at 15:00 UTC
Product according to CISA: Sophos Firewall 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

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.

An authentication bypass vulnerability in User Portal and Webadmin of Sophos Firewall allows for remote code execution.

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).