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

Q: How do I fix CVE-2024-21762?

fortiproxy: upgrade to 2.0.14, 7.0.15, 7.2.9, 7.4.3; fortios: upgrade to 6.0.18, 6.2.16, 6.4.15, 7.0.14, 7.2.7, 7.4.3. Exact commands for each OS are on this page.

Q: Is CVE-2024-21762 being exploited?

Yes. CVE-2024-21762 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

Q: What does CVE-2024-21762 affect?

CVE-2024-21762 affects fortiproxy, fortios. Severity is critical (CVSS 9.8). A out-of-bounds write vulnerability in Fortinet FortiOS 7.4.0 through 7.4.2, FortiOS 7.2.0 through 7.2.6, FortiOS 7.0.0 through 7.0.13, FortiOS 6.4.0 through 6.4.14, FortiOS 6.2.0 through 6.2.15, FortiOS 6.0 all versions, FortiProxy 7.4.0 t

Q: How urgent is CVE-2024-21762?

Priority 100/100. Critical severity; EPSS top 1%: very likely to be exploited; Exploited in the wild (CISA KEV); Used in ransomware campaigns; Public exploit reference; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

100

Patch now

CRITICAL 9.8EXPLOITEDREMOTEUPGRADEUPGRADE

CVE-2024-21762 is a critical-severity flaw (CVSS 9.8) affecting fortiproxy, fortios, reported as exploited in the wild. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A out-of-bounds write vulnerability in Fortinet FortiOS 7.4.0 through 7.4.2, FortiOS 7.2.0 through 7.2.6, FortiOS 7.0.0 through 7.0.13, FortiOS 6.4.0 through 6.4.14, FortiOS 6.2.0 through 6.2.15, FortiOS 6.0 all versions, FortiProxy 7.4.0 through 7.4.2, FortiProxy 7.2.0 through 7.2.8, FortiProxy 7.0.0 through 7.0.14, FortiProxy 2.0.0 through 2.0.13, FortiProxy 01.02 all versions, FortiProxy 1.2 all versions, FortiProxy 01.01 all versions, FortiPr

Why this priority

Critical severity
EPSS top 1%: very likely to be exploited
Exploited in the wild (CISA KEV)
Used in ransomware campaigns
Public exploit reference
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	83.4% (top 1%)
CISA exploited list	Yes, fix due 2024-02-16, used in ransomware
Weakness	CWE-787
Published	2024-02-09
Last modified	2026-10-22

Publisher (CNA): Fortinet, Inc. · Vendor: fortinet

Last updated 2026-10-22 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2024-02-09Published CVE record published
2024-02-09Exploited Added to the CISA Known Exploited Vulnerabilities list
2024-02-16Deadline CISA due date for US federal agencies to patch
2026-10-22 19:20 UTCUpdated Record last modified

fortinet fortiproxy UPGRADE

Affected: >= 1.0.0 and < 2.0.14 · >= 7.0.0 and < 7.0.15 · >= 7.2.0 and < 7.2.9 · >= 7.4.0 and < 7.4.3

Fixed in: 2.0.14, 7.0.15, 7.2.9, 7.4.3

Safe to downgrade to: a release before 1.0.0

1. Check installed version

apt-cache policy fortiproxy || rpm -q fortiproxy || fortiproxy --version

2. UPGRADE to 2.0.14 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade fortiproxy

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade fortiproxy

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 1.0.0 (Debian / Ubuntu)

apt-cache madison fortiproxy sudo apt install fortiproxy=<VERSION_BEFORE_1.0.0> sudo apt-mark hold fortiproxy

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list fortiproxy sudo dnf downgrade fortiproxy-<VERSION_BEFORE_1.0.0> sudo dnf versionlock add fortiproxy

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

fortinet fortios UPGRADE

Affected: >= 6.0.0 and < 6.0.18 · >= 6.2.0 and < 6.2.16 · >= 6.4.0 and < 6.4.15 · >= 7.0.0 and < 7.0.14 · >= 7.2.0 and < 7.2.7 · >= 7.4.0 and < 7.4.3

Fixed in: 6.0.18, 6.2.16, 6.4.15, 7.0.14, 7.2.7, 7.4.3

Safe to downgrade to: a release before 6.0.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Exact fixes by distribution

Fedora 46 · python-streamlink · FIXED · 8.6.2-1.fc46 · FEDORA-2026-a56fcfdc08 · source

sudo dnf upgrade --advisory=FEDORA-2026-a56fcfdc08

Fedora ELN · valgrind · FIXED · 3.28.0-1.eln159 · FEDORA-2026-c593ef1d15 · source

sudo dnf upgrade --advisory=FEDORA-2026-c593ef1d15

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

GitHub PoC: h4x0r-dz/CVE-2024-21762 (150 stars)
GitHub PoC: BishopFox/cve-2024-21762-check (107 stars)
GitHub PoC: r4p3c4/CVE-2024-21762-Exploit-PoC-Fortinet-SSL-VPN-Check (16 stars)
GitHub PoC: AlexLondan/CVE-2024-21762-Fortinet-RCE-ALLWORK

Advisories and coverage

Official advisories

IPA Japan Security Alerts: 更新：Fortinet 製 FortiOS SSL VPN の脆弱性対策について(CVE-2024-21762) 2024-02-25
CERT-FR Alerts: [MàJ] Vulnérabilité dans Fortinet FortiOS (09 février 2024) 2024-02-09

Verify at the official source NVD · CVE Program · CISA KEV catalog · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2024-21762?

fortiproxy: upgrade to 2.0.14, 7.0.15, 7.2.9, 7.4.3; fortios: upgrade to 6.0.18, 6.2.16, 6.4.15, 7.0.14, 7.2.7, 7.4.3. Exact commands for each OS are on this page.

Is CVE-2024-21762 being exploited?

Yes. CVE-2024-21762 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

What does CVE-2024-21762 affect?

CVE-2024-21762 affects fortiproxy, fortios. Severity is critical (CVSS 9.8). A out-of-bounds write vulnerability in Fortinet FortiOS 7.4.0 through 7.4.2, FortiOS 7.2.0 through 7.2.6, FortiOS 7.0.0 through 7.0.13, FortiOS 6.4.0 through 6.4.14, FortiOS 6.2.0 through 6.2.15, FortiOS 6.0 all versions, FortiProxy 7.4.0 t

How urgent is CVE-2024-21762?

Priority 100/100. Critical severity; EPSS top 1%: very likely to be exploited; Exploited in the wild (CISA KEV); Used in ransomware campaigns; Public exploit reference; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

Software pages

Fortinet FortiOS vulnerabilities · Fortinet vulnerabilities

Related CVEs

CVE-2025-61624 MEDIUM 6.0 EXPLOITED UPGRADE UPGRADE Fortinet Multiple Products Path Traversal Vulnerability

References

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