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ExploitedIn CISA KEVFix available

CVE-2020-12812

Exploitation confirmed. First attested on 2021-11-03 by CISA-ADP, CISA KEV, GCVE · kevintel.

  • Published2020-07-24
  • Fixed in6.2.4 · 6.0.10
  • WeaknessCWE-178 · CWE-287

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

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.

Timeline

dates in UTC
  1. 2020-07-2423:15CVE publishedNVD
  2. 2021-11-03Added to the CISA KEV catalogCISA KEV
  3. 2021-11-03Listed as exploited by GCVEGCVE
  4. 2021-11-03Exploitation first reportedCISA KEV
  5. 2026-08-1203:55SSVC exploitation set to activeCISA-ADP

Observed activity

isMalicious corpus · updated 2026-11-03 21:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2020-12812?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2020-12812?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Fortinet FortiOS
BranchAffectedFixed in
6.2≥ 6.2.0, < 6.2.46.2.4
6.0< 6.0.106.0.10
6.4= 6.4.0no fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Products declared by the CNA1 product

As fortinet, the CNA that assigned this CVE, declared them in the CVE record; versions as written.

  • Fortinet FortiOS
    Affected
    • = FortiOS 6.4.0, 6.2.0 to 6.2.3, 6.0.9 and belowno fix stated

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2020-07-24

Fix

  1. Update Fortinet FortiOS to 6.2.4 · 6.0.10
  2. CISA’s required action: Apply updates per vendor instructions.due 2022-05-03

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub
Metasploit modules
none listed
Metasploit Framework

CISA Known Exploited Vulnerability

Date Added
2021-11-03
Patch Due Date
2022-05-03
Ransomware Use
Known
Required Action
Apply updates per vendor instructions.

Sources

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published
2020-07-24
Last Modified
2026-10-02
NVD status
Analyzed
GitHub Advisory
GHSA-r9cj-q2hj-hfq9

Frequently asked questions

What is 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.

Is CVE-2020-12812 actively exploited?

Yes. CVE-2020-12812 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, meaning it has been confirmed as actively exploited in the wild. CISA requires federal agencies to patch by 2022-05-03.

What is the CVSS score for CVE-2020-12812?

CVE-2020-12812 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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Sources for this record