CVE-2024-21762

critical

Description

A out-of-bounds write in Fortinet FortiOS versions 7.4.0 through 7.4.2, 7.2.0 through 7.2.6, 7.0.0 through 7.0.13, 6.4.0 through 6.4.14, 6.2.0 through 6.2.15, 6.0.0 through 6.0.17, FortiProxy versions 7.4.0 through 7.4.2, 7.2.0 through 7.2.8, 7.0.0 through 7.0.14, 2.0.0 through 2.0.13, 1.2.0 through 1.2.13, 1.1.0 through 1.1.6, 1.0.0 through 1.0.7 allows attacker to execute unauthorized code or commands via specifically crafted requests

From the Tenable Blog

CVE-2024-21762: Critical Fortinet FortiOS Out-of-Bound Write SSL VPN Vulnerability

Published: 2024-02-09

Fortinet warns of “potentially” exploited flaw in the SSL VPN functionality of FortiOS, as government agencies warn of pre-positioning by Chinese state-sponsored threat actors in U.S. critical infrastructure through exploitation of known vulnerabilities

References

https://www.securityweek.com/threat-actor-allegedly-selling-fortinet-firewall-zero-day-exploit/

https://www.darkreading.com/vulnerabilities-threats/fortinet-zero-day-arbitrary-code-execution

https://www.cisa.gov/news-events/alerts/2025/04/11/fortinet-releases-advisory-new-post-exploitation-technique-known-vulnerabilities

https://www.bleepingcomputer.com/news/security/fortinet-hackers-retain-access-to-patched-fortigate-vpns-using-symlinks/

https://thehackernews.com/2025/04/fortinet-warns-attackers-retain.html

https://isc.sans.edu/diary/rss/30762

https://www.bleepingcomputer.com/news/security/critical-fortinet-flaw-may-impact-150-000-exposed-devices/

https://www.bleepingcomputer.com/news/security/new-fortinet-rce-flaw-in-ssl-vpn-likely-exploited-in-attacks/

https://github.com/h4x0r-dz/CVE-2024-21762

https://www.tenable.com/blog/verizon-2025-dbir-tenable-research-collaboration

https://www.tenable.com/blog/cve-2024-55591-fortinet-authentication-bypass-zero-day-vulnerability-exploited-in-the-wild

https://www.tenable.com/blog/cve-2023-48788-critical-fortinet-forticlientems-sql-injection-vulnerability

https://www.tenable.com/blog/cve-2024-21762-critical-fortinet-fortios-out-of-bound-write-ssl-vpn-vulnerability

https://fortiguard.com/psirt/FG-IR-24-015

Details

Source: Mitre, NVD

Published: 2024-02-09

Updated: 2024-11-29

Known Exploited Vulnerability (KEV)

Risk Information

CVSS v2

Base Score: 10

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

Severity: Critical

CVSS v3

Base Score: 9.8

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: Critical

EPSS

EPSS: 0.9137

Vulnerability Watch

Tenable Research has classified this CVE under the following Vulnerability Watch classification, which includes active and historical (inactive) classifications. You can learn more about these classifications on our blog.

Vulnerability of Interest

Detections

Analytics