CVE-2025-7624

Critical

Published: 21 July 2025

Published

21 July 2025

Modified

17 November 2025

KEV Added

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Patch

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CVSS Score 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Score 0.0044 63.2th percentile

Risk Priority 20 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-7624 is a critical-severity SQL Injection (CWE-89) vulnerability in Sophos Firewall Firmware. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 36.8% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 CM-7 (Least Functionality) and SI-10 (Information Input Validation).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190). What defenders deploy: see the NIST 800-53 controls recommended below.

Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

SI-2 Flaw Remediation good match

prevent

SI-2 requires timely patching of the SQL injection flaw in the legacy SMTP proxy of Sophos Firewall versions older than 21.0 MR2.

SI-10 Information Input Validation good match

prevent

SI-10 enforces validation of SMTP inputs to prevent injection of malicious SQL payloads into the proxy's database queries.

CM-7 Least Functionality good match

prevent

CM-7 restricts the firewall to least functionality by disabling the legacy transparent SMTP proxy and unnecessary email quarantining policies required for exploitation.

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access

Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.

attack.mitre.org →

Why these techniques?

Direct SQL injection in public-facing SMTP proxy enables unauthenticated remote exploitation of the firewall application, leading to RCE.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

An SQL injection vulnerability in the legacy (transparent) SMTP proxy of Sophos Firewall versions older than 21.0 MR2 (21.0.2) can lead to remote code execution, if a quarantining policy is active for Email and SFOS was upgraded from a version…

older than 21.0 GA.

Deeper analysisAI

CVE-2025-7624 is an SQL injection vulnerability (CWE-89) in the legacy (transparent) SMTP proxy of Sophos Firewall. It affects versions older than 21.0 MR2 (21.0.2), but only under specific conditions: a quarantining policy must be active for Email, and the Sophos Firewall OS (SFOS) must have been upgraded from a version older than 21.0 GA. Successful exploitation can lead to remote code execution, with a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

The vulnerability enables remote attackers to inject malicious SQL payloads through the SMTP proxy, requiring no privileges, user interaction, or special access beyond network reachability. Exploitation grants high-impact remote code execution on the firewall, allowing full compromise of confidentiality, integrity, and availability of the affected system.

The Sophos security advisory at https://www.sophos.com/en-us/security-advisories/sophos-sa-20250721-sfos-rce provides details on mitigation and patches.