Report · SecurityWeekAbout CVE-2025-9242Published 13 Nov 2025

Critical WatchGuard Firebox Vulnerability Exploited in Attacks

Source SecurityWeek

Authoritative record:CVE-2025-9242· Critical 9.3

Exploited in the wild · KEV due 3 Dec 2025 : apply the vendor's fix or mitigations to affected systems now.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 4.0 base score

9.3Critical

How severe the flaw is on the 0–10 CVSS scale.

KEV deadline: 3 Dec 2025 US federal agencies must patch by this date; a sensible deadline for everyone else. Other KEV due dates

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: High
Vulnerable system integrity: High
Vulnerable system availability: High
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: High: There is a total loss of confidentiality, resulting in all information within the Vulnerable System being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.
Vulnerable system integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the vulnerable system. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the vulnerable system.
Vulnerable system availability: High: There is a total loss of availability, resulting in the attacker being able to fully deny access to resources in the Vulnerable System; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the Vulnerable System (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

t = 0 is the CVE’s publication on cve.org

Disclosed: evidence found.
CVE published 17 Sep 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: evidence found.
Listed in CISA KEV 56 days after disclosure
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

CVE ID reserved
by WatchGuard Technologies, Inc.
20 Aug 202511:08 UTC, 28 days before disclosure
CVE published
on cve.org
17 Sep 202507:29 UTC, t = 0
In Threat Radar
record ingested
17 Sep 202507:35 UTC, 6 minutes after disclosure
Added to CISA KEV (opens in a new tab)
exploitation confirmed
12 Nov 2025, 56 days after disclosure
KEV remediation due
US federal deadline
3 Dec 2025, 77 days after disclosure

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA KEV (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

remote

What to do

AI-suggested

Organizations should immediately verify the presence of WatchGuard Firebox devices within their networks and identify their firmware versions. In the interim, restrict network access to management interfaces of Firebox devices to trusted IP addresses only, ideally via VPN or secure management networks. Implement strict network segmentation to limit exposure of the firewall to untrusted networks. Deploy intrusion detection and prevention systems (IDS/IPS) with signatures tuned to detect exploit attempts targeting this vulnerability. Conduct thorough vulnerability scanning and penetration testing to identify potential exposure. Enhance logging and monitoring on Firebox devices and network infrastructure to detect anomalous activities indicative of exploitation attempts. Educate security teams about the vulnerability and establish incident response plans tailored to potential exploitation scenarios. Consider deploying additional firewall or endpoint protections to mitigate risk until patches are applied.

Description

CVE-2025-9242 is a critical vulnerability in WatchGuard Firebox firewalls that allows unauthenticated remote code execution. This flaw enables attackers to execute arbitrary code on vulnerable devices without needing authentication, posing a severe risk to network security. Although no known exploits in the wild have been reported yet, the high CVSS score of 9.3 indicates significant potential impact. European organizations relying on WatchGuard Firebox devices for perimeter defense could face data breaches, network compromise, or service disruption if exploited. Immediate patching and network segmentation are essential to mitigate this risk. Countries with high adoption of WatchGuard products and critical infrastructure reliance on these firewalls are particularly at risk. The vulnerability's ease of exploitation and broad impact on confidentiality, integrity, and availability justify a critical severity rating. Defenders should prioritize vulnerability scanning, deploy compensating controls, and monitor for suspicious activity targeting Firebox devices.

Impact

For European organizations, exploitation of CVE-2025-9242 could lead to severe consequences including unauthorized access to internal networks, data exfiltration, disruption of critical services, and potential lateral movement by attackers. Organizations in sectors such as finance, healthcare, government, and critical infrastructure that rely on WatchGuard Firebox firewalls for network security are at heightened risk. Compromise of these devices can undermine trust in network defenses, expose sensitive personal and corporate data, and cause operational downtime. The impact extends to regulatory compliance, as breaches involving personal data could trigger GDPR violations and associated penalties. Additionally, the ability to execute code remotely without authentication means attackers could deploy ransomware or other malware, amplifying the threat. The broad scope of affected systems and the firewall's strategic position in network architecture make this vulnerability particularly dangerous for European enterprises and public sector entities.

Summary

CVE-2025-9242 is a critical security vulnerability affecting WatchGuard Firebox firewall devices, enabling unauthenticated remote code execution (RCE). This vulnerability allows attackers to send crafted network packets or requests to the firewall, bypassing authentication mechanisms and executing arbitrary code with system-level privileges. The flaw arises from improper input validation or unsafe deserialization within the firewall's management or network processing components. Exploitation can lead to full compromise of the firewall, allowing attackers to manipulate firewall rules, intercept or redirect traffic, deploy malware, or pivot into internal networks. The vulnerability has a CVSS score of 9.3, reflecting its high impact and exploitability. Although no active exploitation has been reported, the critical nature of the flaw and the widespread use of WatchGuard Firebox devices in enterprise and government networks make it a significant threat. The lack of publicly available patches or mitigations at the time of reporting increases urgency for organizations to implement interim protective measures. This vulnerability affects all versions of Firebox devices that have not been updated or patched, though specific affected versions were not detailed. The attack vector is remote and requires no authentication or user interaction, increasing the risk of automated exploitation attempts. Given the firewall's role as a network perimeter defense, successful exploitation can compromise confidentiality, integrity, and availability of organizational networks.

References

securityweek.com/critical-watchguard-firebox-vulnerability-exploited-in-attacks/ (opens in a new tab)

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Exploitation evidence

Timeline

What to do

Description

AI analysisMachine-generated, updated 13 Nov 2025, 12:41 UTC

References

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