Authentication Bypass in Fortinet FortiOS and FortiProxy Grants Super-Admin Access
CISA: Fortinet FortiOS and FortiProxy Authentication Bypass Vulnerability
CVSS 3.1
8.1high
EPSS
7%p94
Published
()
KEV added
AI analysis
CVE-2025-24472 is an authentication bypass (CWE-288) in the Fortinet Security Fabric of FortiOS and FortiProxy. A remote, unauthenticated attacker who already knows the serial numbers of both the upstream and downstream devices can send crafted CSF proxy requests to gain super-admin privileges on the downstream device; the attack only works where the Security Fabric is enabled, and the need for serial-number knowledge raises attack complexity. An attacker gains full super-admin control of the downstream Fortinet device, which can serve as a foothold for network-wide compromise. Organizations running affected FortiOS 7.0.x or FortiProxy 7.0.x/7.2.x builds with Security Fabric enabled are in scope. The flaw was added to CISA's KEV catalog on 2025-03-18 with known ransomware use, and multiple ransomware groups (including Gunra, SuperBlack, Mora_001 and Qilin operators) have been reported exploiting Fortinet firewall flaws in recent campaigns.
What to do: Upgrade FortiOS 7.0.x and FortiProxy 7.0.x/7.2.x deployments to the fixed releases listed in the Fortinet PSIRT advisory for CVE-2025-24472, and identify any devices where the Security Fabric is enabled and serial numbers of peer devices may be discoverable. As interim mitigation, restrict or disable Security Fabric (CSF) connectivity toward untrusted peers and limit access to the CSF proxy handling path. Because the flaw is KEV-listed with known ransomware use, federal agencies must apply vendor mitigations per BOD 22-01 or discontinue use, and all defenders should review device logs for unexpected super-admin sessions and anomalous CSF proxy traffic.
Affected
Fortinet FortiOS
7.0.0 through 7.0.16
Fortinet FortiProxy
7.0.0 through 7.0.19
Fortinet FortiProxy
7.2.0 through 7.2.12
Estimated exposure
masshundreds of thousands of deployed Fortinet appliances plausibly affected; the practical subset is those with Security Fabric enabled — Fortinet is one of the largest firewall/secure-web-gateway vendors and public internet scans routinely surface hundreds of thousands of exposed FortiGate/FortiProxy appliances, but exploitation additionally requires Security Fabric to be…
Order-of-magnitude estimate by the model from install counts, market share and public scan data it knows; verify before quoting.
Description
An Authentication Bypass Using an Alternate Path or Channel vulnerability [CWE-288] affecting FortiOS 7.0.0 through 7.0.16 and FortiProxy 7.2.0 through 7.2.12, 7.0.0 through 7.0.19 may allow a remote unauthenticated attacker with prior knowledge of upstream and downstream devices serial numbers to gain super-admin privileges on the downstream device, if the Security Fabric is enabled, via crafted CSF proxy requests.
CISA Known Exploited Vulnerability
Affected
Fortinet FortiOS and FortiProxy
Required action
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
CISA, FBI, and South Korean agencies warn Gunra ransomware, with 51 victims since April 2025, exploits Fortinet flaws for double-extortion attacks on critical infrastructure.
CISA, the FBI, and South Korean agencies warned of Gunra ransomware attacks targeting healthcare, financial services, government, and professional services worldwide. The Conti-derived operation exploits internet-facing Fortinet FortiOS and FortiProxy flaws CVE-2024-55591 and CVE-2025-24472 for initial access, then deploys double extortion with Salsa20/ChaCha20 encryption and publishes non-payers on a leak site within five to seven days. Ransomware.Live lists 51 victims since April 2025, mostly in South Korea, Brazil, Spain, Thailand, and Hong Kong. The group uses Impacket tools for SMB lateral movement and NTDS credential dumping, tampers with VDI authentication to accept a designated OTP value to bypass MFA, and launched a RaaS affiliate program in January 2026 under the new alias Golden Community.