Critical Fortinet FortiClient EMS flaw exploited for Remote Code Execution
Vulnerabilities mentionedAll →
| CVE | Vulnerability | CVSS | EPSS | Flags | Affected | Exposure | Published |
|---|---|---|---|---|---|---|---|
| CVE-2023-48788 | Unauthenticated SQL Injection in Fortinet FortiClient EMS Fortinet FortiClient EMS — the central management server for FortiClient endpoint deployments — contains a SQL injection flaw (CWE-89) in versions 7.0.1 through 7.0.10 and 7.2.0 through 7.2.2. The CVSS 3.1 vector (AV:N/AC:L/PR:N/UI:N) shows it can be triggered remotely with no credentials and no user interaction: an unauthenticated attacker sends specially crafted packets to the vulnerable management server and can execute unauthorized code or commands. Successful exploitation effectively yields remote code execution on the EMS server and access to its database, enabling follow-on actions such as credential theft, abuse of endpoint management functions, and ransomware deployment. Any organization running the affected EMS versions is exposed, especially where the management server is reachable from the internet. Exploitation is confirmed in the wild: CISA added the bug to the KEV catalog on 2024-03-25 with known ransomware use, and EPSS assigns a ~98.4% probability of exploitation within 30 days (100th percentile). Do: Upgrade FortiClient EMS to the fixed releases per Fortinet's advisory for this CVE (7.2.3 and 7.0.11 or later, i.e., beyond the 7.2.2 and 7.0.10 affected ranges); the CISA KEV required action is to apply vendor mitigations or discontinue use if mitigations are unavailable. Until patched, limit exposure of the EMS web interface to untrusted networks and hunt for signs of compromise — anomalous requests to the management console, unexpected database or admin activity, and follow-on ransomware behavior — since exploitation with known ransomware use is confirmed. | 9.8 | 98% | KEV ransomware |
| largetens of thousands of EMS deployments worldwide, with a smaller subset (likely thousands) internet-exposed | |
| CVE-2026-21643 | Unauthenticated SQL Injection to Code Execution in Fortinet FortiClient EMS 7.4.4 CVE-2026-21643 is a critical SQL injection flaw (CWE-89, improper neutralization of special elements used in an SQL command) in Fortinet FortiClient EMS 7.4.4, scored 9.8 critical (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H). An unauthenticated remote attacker can trigger it by sending specifically crafted HTTP requests to the EMS server, and successful injection allows execution of unauthorized code or commands, yielding high confidentiality, integrity, and availability impact. Any organization running the affected FortiClient EMS release is exposed, with internet-facing EMS management servers at greatest risk. Exploitation is confirmed: CISA added the flaw to the Known Exploited Vulnerabilities catalog on 2026-04-13, EPSS assigns a 94.1% probability of exploitation within 30 days (99.9th-plus percentile), and news reports describe active zero-day exploitation that prompted Fortinet to issue emergency patches, alongside related FortiClient EMS hotfixes (CVE-2026-35616). Do: Upgrade affected FortiClient EMS 7.4.4 deployments using the emergency patch/hotfix Fortinet has released (see the Fortinet PSIRT advisory for fixed builds), prioritizing internet-exposed EMS servers; federal agencies must satisfy the BOD 22-01 requirement per the KEV listing. Until patched, restrict public exposure of the EMS web interface and review web access and database logs for signs of crafted HTTP requests or unexpected command execution. | 9.8 | 94% | KEV PoC |
| largeon the order of tens of thousands of FortiClient EMS server deployments (estimate) |
Full article407 words · extracted from securityaffairs.com · click to collapse
Attackers are exploiting a critical Fortinet FortiClient EMS flaw (CVE-2026-21643) that allows remote code execution via SQL injection.
A critical Fortinet FortiClient EMS vulnerability, tracked as CVE-2026-21643 (CVSS score of 9.1), is now being actively exploited.
Defused researchers warn that threat actors are exploiting the vulnerability in Fortinet’s FortiClient EMS platform.
“Fortinet Forticlient EMS CVE-2026-21643 – currently marked as not exploited on CISA and other Known Exploited Vulnerabilities (KEV) lists – has seen first exploitation already 4 days ago according to our data Attackers can smuggle SQL statements through the “Site”-header inside an HTTP request According to Shodan, close to 1000 instances of Forticlient EMS are publicly exposed.” Defused wrote on X.
— Defused (@DefusedCyber) March 28, 2026🚨 Fortinet Forticlient EMS CVE-2026-21643 – currently marked as not exploited on CISA and other Known Exploited Vulnerabilities (KEV) lists – has seen first exploitation already 4 days ago according to our data
Attackers can smuggle SQL statements through the "Site"-header… pic.twitter.com/pHwl2qMVsj
In February, Fortinet issued an urgent advisory to address the critical FortiClientEMS vulnerability. The vulnerability is an improper neutralization of special elements used in an SQL Command (‘SQL Injection’) issue in FortiClientEMS. An unauthenticated attacker can trigger the flaw to execute unauthorized code or commands via specifically crafted HTTP requests.
“An improper neutralization of special elements used in an SQL Command (‘SQL Injection’) vulnerability [CWE-89] in FortiClientEMS may allow an unauthenticated attacker to execute unauthorized code or commands via specifically crafted HTTP requests.” reads the advisory.
A successful attack could give attackers an initial foothold in the target network, enabling lateral movement or malware deployment.
The vulnerability was internally discovered and reported by Gwendal Guégniaud of Fortinet Product Security team.
Below are the affected versions:
| Version | Affected | Solution |
|---|---|---|
| FortiClientEMS 8.0 | Not affected | Not Applicable |
| FortiClientEMS 7.4 | 7.4.4 | Upgrade to 7.4.5 or above |
| FortiClientEMS 7.2 | Not affected | Not Applicable |
In February, the vendor did not disclose whether the vulnerability is currently being actively exploited in the wild.
Despite not yet appearing in major exploited lists, real-world attacks have already been observed.
Shadowserver researchers report approximately 2,000 FortiClient EMS instances exposed online, most of them in the U.S. (756) and Europe (683).
In March 2024, the U.S. Cybersecurity and Infrastructure Security Agency (CISA) added a FortiClient EMS SQL Injection Vulnerability, tracked as CVE-2023-48788, to its Known Exploited Vulnerabilities (KEV) catalog.
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