Fortinet · FortiOS and FortiProxy · Fortinet FortiOS and FortiProxy Authentication Bypass Vulnerability
Verdict
Patch first · actively exploited, reachable from the internet without credentials, and in the top 10% of CVEs by near-term exploitation probability
Added to CISA KEV 2025-03-18 · exploited in the wild for 558 days · used in ransomware campaigns
CVSS 8.1 HIGH. The score is a summary; these three components are the part that decides whether something scanning the internet can use it.
| Attack vector | networkreachable over the network, with no local access needed |
|---|---|
| Privileges required | noneneeds no credentials at all |
| User interaction | nonecan be triggered with nobody interacting with the page or request |
| Base vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
| Weakness | CWE-288 |
This describes the vulnerability. It says nothing about whether your systems run it.
EPSS puts the probability of exploitation in the next 30 days at 0.0723, which places it in the top 10% of all tracked CVEs. The percentile is the more useful half: 0.18 in absolute terms sounds low until you know most of the internet-facing software in the world scores under that.
| EPSS probability | 0.0723 |
|---|---|
| Percentile | 0.941 — top 10% |
| Added to KEV | 2025-03-18 |
|---|---|
| Days exploited | 558 |
| Federal remediation due | not set |
| Ransomware use | known to be used in ransomware campaigns |
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
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.