Auth bypass in Fortinet Fortios

CVE-2020-12812

An improper authentication vulnerability in SSL VPN in FortiOS 6.4.0, 6.2.0 to 6.2.3, 6.0.9 and below may result in a user being able to log in successfully without being prompted for the second factor of authentication (FortiToken) if they changed the case of their username.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.454 (98.8th percentile), scored .

Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 99th percentile — 98.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2020-12812: fell from 0.493 to 0.454.

EPSS over last 30 days · oldest: 0.493 · newest: 0.454 · change: -0.040

Affected products

  • Fortinet Fortios — versions 6.4.0
  • Fortinet Fortios — versions FortiOS 6.4.0, 6.2.0 to 6.2.3, 6.0.9 and below

Weakness classification (CWE)

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on . CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: .

Required action: Apply updates per vendor instructions.

Known ransomware campaign use: yes.

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2020-12812?
CVE-2020-12812 is a critical-severity vulnerability in Fortinet Fortios, classified under Improper Handling of Case Sensitivity. CVSS score: 9.8/10. Published 2020-07-24.
How severe is CVE-2020-12812?
Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2020-12812 known to be exploited?
Yes. CVE-2020-12812 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), indicating it is being actively exploited. 8 public proof-of-concept repositories are indexed.