CVE-2021-36166
An improper authentication vulnerability in FortiMail before 7.0.1 may allow a remote attacker to efficiently guess one administrative account's authentication token by means of the observation of certain system's properties.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.47%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
An improper authentication vulnerability in FortiMail before 7.0.1 may allow a remote attacker to efficiently guess one administrative account's authentication token by means of the observation of certain system's properties.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 1.47% probability · 74th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-330
- Affected
- fortinet/fortimail
- Source
- psirt@fortinet.com
EPSS 1.5% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://fortiguard.com/psirt/FG-IR-21-028Vendor Advisory
- https://fortiguard.com/psirt/FG-IR-21-028Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.