CVE-2025-25256: Proof of Concept Released for Critical Fortinet FortiSIEM Command Injection Vulnerability

Exploit code is reportedly available for a critical command injection vulnerability affecting Fortinet FortiSIEM devices.

Background

On August 12, Fortinet published a security advisory (FG-IR-25-152) for CVE-2025-25256, a critical command injection vulnerability affecting Fortinet FortiSIEM.

CVE Description CVSSv3
CVE-2025-25256 Fortinet FortiSIEM Command Injection Vulnerability 9.8

Analysis

CVE-2025-25256 is a critical operating system (OS) command injection vulnerability affecting Fortinet FortiSIEM. A remote, unauthenticated attacker can exploit this flaw to execute arbitrary code using specially crafted requests.

According to the advisory, exploitation of this flaw does not “produce distinctive” indicators of compromise (IoCs). As such, it may be difficult to identify that a device has been compromised.

Historical Exploitation of Fortinet Devices

Fortinet vulnerabilities have historically been common targets for cyber attackers, with 20 CVEs currently on the Cybersecurity and Infrastructure Security Agency’s (CISA) Known Exploited Vulnerabilities (KEV) list. The following table outlines some of the most impactful Fortinet vulnerabilities in recent years.

CVE Description Patched Tenable Blog
CVE-2025-32756 Fortinet FortiVoice, FortiMail, FortiNDR, FortiRecorder and FortiCamera Arbitrary Code Execution Vulnerability May 2025 CVE-2025-32756: Zero-Day Vulnerability in Multiple Fortinet Products Exploited in the Wild
CVE-2024-55591 Fortinet Authentication Bypass in FortiOS and FortiProxy January 2025 CVE-2024-55591: Fortinet Authentication Bypass Zero-Day Vulnerability Exploited in the Wild
CVE-2024-21762 Fortinet FortiOS Out-of-bound Write Vulnerability in sslvpnd February 2024 CVE-2024-21762: Critical Fortinet FortiOS Out-of-Bound Write SSL VPN Vulnerability
CVE-2023-27997 FortiOS and FortiProxy Heap-Based Buffer Overflow Vulnerability June 2023 CVE-2023-27997: Heap-Based Buffer Overflow in Fortinet FortiOS and FortiProxy SSL-VPN (XORtigate)
CVE-2022-42475 FortiOS and FortiProxy Heap-Based Buffer Overflow Vulnerability December 2022 CVE-2022-42475: Fortinet Patches Zero Day in FortiOS SSL VPNsAA23-250A: Multiple Nation-State Threat Actors Exploit CVE-2022-47966 and CVE-2022-42475
CVE-2022-40684 FortiOS and FortiProxy Authentication Bypass Vulnerability October 2022 CVE-2022-40684: Critical Authentication Bypass in FortiOS and FortiProxy

Proof of concept

At the time the advisory was published by Fortinet on August 12, they warned that “practical exploit code” had been found in the wild, though they did not provide a link to the exploit. Tenable Research has attempted to identify a functional proof-of-concept (PoC) for this flaw, however, we have not successfully located one as of the time this blog was published.

Solution

The following table details the affected and fixed versions of Fortinet devices for CVE-2025-25256:

Product Version Affected Range Fixed Version
FortiSIEM 5.4 All Versions of 5.4 Migrate to a fixed release
FortiSIEM 6.1 All Versions of 6.1 Migrate to a fixed release
FortiSIEM 6.2 All Versions of 6.2 Migrate to a fixed release
FortiSIEM 6.3 All Versions of 6.3 Migrate to a fixed release
FortiSIEM 6.4 All Versions of 6.4 Migrate to a fixed release
FortiSIEM 6.5 All Versions of 6.5 Migrate to a fixed release
FortiSIEM 6.6 All Versions of 6.6 Migrate to a fixed release
FortiSIEM 6.7 6.7.0 through 6.7.9 6.7.10 or above
FortiSIEM 7.0 7.0.0 through 7.0.3 7.0.4 or above
FortiSIEM 7.1 7.1.0 through 7.1.7 7.1.8 or above
FortiSIEM 7.2 7.2.0 through 7.2.5 7.2.6 or above
FortiSIEM 7.3 7.3.0 through 7.3.1 7.3.2 or above
FortiSIEM 7.4 Not Affected Not Applicable

Fortinet’s security advisory advises if immediate patching is not able to be performed, they recommend limiting access to the phMonitor port of 7900. We strongly recommend reviewing the advisory for updates as well as the latest on mitigation or indicators of compromise (IoCs).

Identifying affected systems

A list of Tenable plugins for this vulnerability can be found on the individual CVE page for CVE-2025-25256 as they’re released. This link will display all available plugins for this vulnerability, including upcoming plugins in our Plugins Pipeline.

Additionally, customers can utilize Tenable Attack Surface Management to identify public facing assets running Fortinet devices by using the following subscription:

Attack Surface Management subscription for Fortinet Devices

Get more information

Join Tenable's Research Special Operations (RSO) Team on the Tenable Community.

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The post CVE-2025-25256: Proof of Concept Released for Critical Fortinet FortiSIEM Command Injection Vulnerability appeared first on Security Boulevard.

13 August 2025


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