CVE-2021-24018

Name: CVE-2021-24018
Creator: NVD / NIST
Published: 2021-08-04T15:15:08.983+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.8/10EPSS 0.76%

Last modified Jun 17, 2026

CVE-2021-24018 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. A buffer underwrite vulnerability in the firmware verification routine of FortiOS before 7.0.1 may allow an attacker located in the adjacent network to potentially execute arbitrary code via a specifically crafted firmware image.. EPSS estimates a 0.76% chance of exploitation in the next 30 days.

Description

A buffer underwrite vulnerability in the firmware verification routine of FortiOS before 7.0.1 may allow an attacker located in the adjacent network to potentially execute arbitrary code via a specifically crafted firmware image.

Metrics

CVSS 3.1

8.8/10

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

EPSS Probability

0.76%

50.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-787

Affected Software

Vendor	Product	Versions
Fortinet	Fortios	< 6.2.10
Fortinet	Fortios	>= 6.4.0, < 6.4.7
Fortinet	Fortios	7.0.0

References

https://fortiguard.com/advisory/FG-IR-21-046Vendor Advisory
https://fortiguard.com/advisory/FG-IR-21-046Vendor Advisory

Timeline

Published: Aug 4, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-24018?

How severe is CVE-2021-24018?

CVE-2021-24018 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 0.76% probability of exploitation in the next 30 days.

How do I fix CVE-2021-24018?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-24018?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST