Report · SecurityWeekAbout CVE-2020-12812Published 29 Dec 2025

Fortinet Warns of New Attacks Exploiting Old Vulnerability

Source SecurityWeek

Authoritative record:CVE-2020-12812· High 7.5

Exploited in the wild · KEV due 3 May 2022 : apply the vendor's fix or mitigations to FortiOS now.

Data as of 26 Oct 2026, 10:12 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

KEV deadline: 3 May 2022 US federal agencies must patch by this date; a sensible deadline for everyone else.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

t = 0 is the CVE’s publication on cve.org

Disclosed: evidence found.
CVE published 24 Jul 2020
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: evidence found.
Listed in CISA KEV 1.3 years after disclosure
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

CVE published
on cve.org
24 Jul 202022:28 UTC, t = 0
Added to CISA KEV (opens in a new tab)
exploitation confirmed · ransomware use known
3 Nov 2021, 1.3 years after disclosure
KEV remediation due
US federal deadline
3 May 2022, 1.8 years after disclosure

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA KEV (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Fortinet FortiOS	Affected =FortiOS 6.4.0, 6.2.0 to 6.2.3, 6.0.9 and below	Fixed in–

AI-suggested

European organizations should immediately verify their FortiOS versions against Fortinet's official advisories and apply all relevant patches addressing CVE-2020-12812. Where patching is not immediately possible, organizations should enforce strict network segmentation and limit administrative access to FortiOS devices. Multi-factor authentication should be reviewed and enhanced, potentially incorporating hardware tokens or certificate-based authentication to reduce reliance on vulnerable 2FA implementations. Continuous monitoring for unusual login attempts or configuration changes on FortiOS devices is essential. Implementing robust logging and alerting mechanisms can help detect exploitation attempts early. Additionally, organizations should conduct regular security audits and penetration testing focused on network security appliances. Employee training on recognizing phishing or social engineering attempts that could facilitate exploitation is also recommended. Coordination with national cybersecurity agencies and sharing threat intelligence can improve preparedness and response.

Description

Tracked as CVE-2020-12812, the exploited FortiOS flaw allows threat actors to bypass two-factor authentication. The post Fortinet Warns of New Attacks Exploiting Old Vulnerability appeared first on SecurityWeek .

Impact

For European organizations, the exploitation of CVE-2020-12812 could have serious consequences. FortiOS devices are widely used across Europe in sectors such as finance, telecommunications, government, and critical infrastructure. Unauthorized access resulting from 2FA bypass can lead to data breaches, network manipulation, and service disruptions. Confidentiality and integrity of sensitive information could be compromised, and availability might be impacted if attackers alter firewall or VPN configurations. The risk is heightened for organizations that have not applied patches or have weak authentication configurations. Given the strategic importance of secure network infrastructure in Europe, successful exploitation could facilitate further lateral movement by attackers, increasing the scope of impact. Although currently rated as low severity, the potential for escalation and the critical nature of affected systems warrant proactive measures. The threat also aligns with ongoing geopolitical tensions where cyberattacks targeting European infrastructure are a concern.

References

securityweek.com/fortinet-warns-of-new-attacks-exploiting-old-vulnerability/ (opens in a new tab)

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Exploitation evidence

Timeline

What to do

Affected software

Description

AI analysisMachine-generated, updated 30 Dec 2025, 22:17 UTC

References

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