CVE-2025-25256: A Critical OS Command Injection Vulnerability in Fortinet FortiSIEM

Overview

In the sphere of cybersecurity, a new vulnerability has surfaced that threatens the security of Fortinet FortiSIEM users. Identified as CVE-2025-25256, this vulnerability is due to an improper neutralization of special elements used in an OS command, generally known as ‘OS Command Injection’. This vulnerability has the potential to affect a wide range of versions of the Fortinet FortiSIEM, making it an urgent issue that requires immediate attention. Essentially, this vulnerability could enable an unauthenticated attacker to execute unauthorized code or commands, potentially leading to system compromise or data leakage.

Vulnerability Summary

CVE ID: CVE-2025-25256
Severity: Critical (CVSS: 9.8)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: System compromise and potential data leakage

Affected Products

Product | Affected Versions

Fortinet FortiSIEM | 7.3.0 through 7.3.1
Fortinet FortiSIEM | 7.2.0 through 7.2.5
Fortinet FortiSIEM | 7.1.0 through 7.1.7
Fortinet FortiSIEM | 7.0.0 through 7.0.3
Fortinet FortiSIEM | Before 6.7.9

How the Exploit Works

The exploit takes advantage of the improper neutralization of special elements used in an OS command in Fortinet FortiSIEM. An attacker can send a specially crafted CLI request that includes malicious code. Because the system does not properly neutralize these special elements, the code is executed, giving the attacker the ability to execute unauthorized commands or code. This execution could potentially result in system compromise or leakage of sensitive data.

Conceptual Example Code

Here’s a conceptual example of how the vulnerability might be exploited through a CLI request:

$ ssh -l unprivileged_user target.example.com
password: 
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$ echo [malicious_payload] | bash

In this conceptual example, the attacker uses SSH to connect to the target system. They then input the malicious payload into the bash shell. If the system is vulnerable to CVE-2025-25256, it doesn’t properly neutralize the special elements in the command and executes the malicious payload.