CVE-2025-6704Network attack vector

Pre-auth code execution via arbitrary file writing

Published Jul 21, 2025 · Updated Jul 21, 2025

Arbitrary file writing in Sophos Firewall before 21.0 MR2 allows remote attackers to execute code through the SPX feature. The SPX feature writes attacker-controlled data to an arbitrary file, but Sophos has not disclosed the responsible code path or request field. Exploitation requires a specific SPX configuration together with High Availability mode and grants code execution before authentication.

CVSS severity9.8
Critical
EPSS probability9.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Arbitrary file writing in Sophos Firewall before 21.0 MR2 allows remote attackers to execute code through the SPX feature. The SPX feature writes attacker-controlled data to an arbitrary file, but Sophos has not disclosed the responsible code path or request field. Exploitation requires a specific SPX configuration together with High Availability mode and grants code execution before authentication.

The record

CVE
CVE-2025-6704
Published
Jul 21, 2025
Updated
Jul 21, 2025
Vendor
Sophos
Product
Sophos Firewall
Classifications
CWE-78, CAPEC-165, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 21, 2025CVE publishedPublication date reported by the CVE source.
  2. Jul 21, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <21.0 MR2 (21.0.2)

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Sophos · Sophos Firewallversion=0 <21.0 MR2 (21.0.2)

Published CVSS scores

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

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
CAPEC-165File Manipulation
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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