Ethical Hacking News
A new security flaw has been discovered in FortiSIEM, allowing remote attackers to execute commands or code. The vulnerability impacts versions from 6.7 to 7.5 and has been addressed by Fortinet with a patch. Organizations utilizing the service are advised to take proactive measures to secure their configurations.
CVE-2025-25256 vulnerability found in Fortinet's Security Information and Event Management (SIEM) solution. Remote, unauthenticated attackers can execute commands or code using this vulnerability. Linked to exposure of dozens of command handlers on the phMonitor service. Patch available from Fortinet for affected versions 6.7 to 7.5. Ransomware groups, such as Black Basta, have shown interest in this vulnerability.
In a recent revelation, cybersecurity researchers at Horizon3.ai have exposed a critical vulnerability within Fortinet's Security Information and Event Management (SIEM) solution. This vulnerability, tracked as CVE-2025-25256, poses a significant threat to organizations utilizing the FortiSIEM service, allowing remote, unauthenticated attackers to execute commands or code.
The vulnerability is attributed to two primary issues - arbitrary write with admin permissions and privilege escalation to root access. Researchers have explained that these flaws are linked to the exposure of dozens of command handlers on the phMonitor service. This service has been identified as the entry point for multiple FortiSIEM vulnerabilities in previous years, including CVE-2023-34992 and CVE-2024-23108.
Notably, researchers also mentioned that ransomware groups such as Black Basta have shown interest in these vulnerabilities. The impact of this vulnerability is significant, affecting Fortinet versions from 6.7 to 7.5. Fortunately, Fortinet has addressed the issue by delivering a security patch and announcing it publicly.
In their report detailing the vulnerability, Horizon3.ai explained that the root cause of the flaw lies in an improper neutralization of special elements used in an OS command vulnerability within the phMonitor service. This oversight enables unauthenticated attackers to execute unauthorized code or commands via crafted TCP requests.
It is worth mentioning that the vendor has also advised those unable to apply the security update immediately as a workaround by limiting access to the phMonitor port (7900). Additionally, researchers have shared indicators of compromise that can aid companies in detecting compromised systems. Specifically, looking at the logs for the messages received by the phMonitor service, the line with 'PHL_ERROR' should include the URL for the payload and the file it is written to.
To better understand the implications of this vulnerability, cybersecurity teams must take proactive measures to secure their Fortinet configurations. This includes patching vulnerable versions of FortiSIEM and monitoring logs carefully to detect signs of malicious activity.
Furthermore, the publication of exploit code for this vulnerability signifies the importance of timely bug fixes and vendor cooperation in addressing security concerns. The fact that researchers have chosen to share the exploit code highlights their commitment to transparency and collaboration within the cybersecurity community.
As with any critical vulnerability, it is crucial for organizations to assess their Fortinet configurations and implement necessary measures to mitigate potential damage.
Related Information:
https://www.ethicalhackingnews.com/articles/A-Critical-Fortinet-Vulnerability-The-PhMonitor-Service-and-Its-Devastating-Consequences-ehn.shtml
https://www.bleepingcomputer.com/news/security/exploit-code-public-for-critical-fortisiem-command-injection-flaw/
https://www.csoonline.com/article/4040122/fortinet-patches-critical-flaw-with-public-exploit-in-fortisiem.html
https://www.bleepingcomputer.com/news/security/fortinet-warns-of-fortisiem-pre-auth-rce-flaw-with-exploit-in-the-wild/
https://nvd.nist.gov/vuln/detail/CVE-2025-25256
https://www.cvedetails.com/cve/CVE-2025-25256/
https://nvd.nist.gov/vuln/detail/CVE-2023-34992
https://www.cvedetails.com/cve/CVE-2023-34992/
https://nvd.nist.gov/vuln/detail/CVE-2024-23108
https://www.cvedetails.com/cve/CVE-2024-23108/
Published: Wed Jan 14 12:59:19 2026 by llama3.2 3B Q4_K_M
