VTA-004560 – Critical SQL Injection Flaw Exposes FortiClient EMS to Remote Code Execution

Fortinet recently published a PSIRT advisory (FG-IR-25-1142) highlighting a critical security flaw in FortiClient EMS, the enterprise management server for Fortinet’s endpoint products. This issue has been catalogued as CVE-2026-21643 and it stems from an SQL Injection vulnerability in version 7.4.4 of FortiClientEMS. At its core, this flaw allows specially crafted HTTP requests to bypass input validation and inject malicious SQL commands into the backend database, enabling an attacker to execute unauthorized code or commands on the system.

What makes this vulnerability particularly serious is its lack of prerequisites for exploitation. An attacker doesn’t need a valid login, elevated privileges or any user interaction all that’s required is network access to the vulnerable EMS server. This “unauthenticated” attack vector dramatically increases the exposure risk, especially in large enterprise environments where EMS systems are often reachable from internal networks. The vulnerability has been assigned a critical severity score (CVSS 9.8/10), underscoring the high potential impact on confidentiality, integrity and availability.

Compared to typical SQL injection flaws which are common but increasingly mitigated through modern frameworks and coding practices, this issue stands out because it affects security management infrastructure itself. FortiClient EMS is used to administer endpoint protection across an organization, compromise of this system could allow attackers not only to disrupt management functions but also to pivot deeper into the environment or manipulate security telemetry. In other words, an attacker leveraging this vulnerability could turn a security tool into a beachhead for further exploitation.

Severity:
Critical

Attack Surface:
Endpoint, Infrastructure, System Management Service

Tactics:
Defense Evasion, Discovery, Execution, Impact, Initial Access, Privilege Escalation

Techniques:
T1190 – Exploit Public-Facing Application
T1505 – Server Software Component: SQL Injection
T1059 – Command and Scripting Interpreter
T1068 – Privilege Escalation
T1562 – Defense Evasion
T1082 – Discovery
T1499 – Impact

Indicator of Compromise:
https://otx.alienvault.com/pulse/698a9322a97db3f0163d2e9c

References:
1. https://fortiguard.fortinet.com/psirt/FG-IR-25-1142

SuperPRO’s Threat Countermeasures Procedures:
where the SQL injection flaw is patched.
2. Restrict network access to the FortiClient EMS management interface by enforcing IP allow-listing and ensuring it is not exposed to untrusted networks.
3. Monitor EMS logs and backend database activity for unexpected SQL queries or anomalous administrative actions.
4. Deploy a Web Application Firewall (WAF) or reverse proxy in front of EMS to detect and block SQL injection patterns targeting HTTP endpoints.
5. Conduct a post-patch integrity check on EMS databases to ensure no unauthorized modifications occurred prior to remediation.

Contributed by: Thivya