CVE-2021-41016: A improper neutralization of special elements used in a command ('command injection') in Fortinet FortiExtende

Q: How do I fix CVE-2021-41016?

fortiextender firmware: upgrade to 4.1.8, 4.2.4, 7.0.2. Exact commands for each OS are on this page.

Q: Is CVE-2021-41016 being exploited?

CVE-2021-41016 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2021-41016 affect?

CVE-2021-41016 affects fortiextender firmware. Severity is high (CVSS 7.8). A improper neutralization of special elements used in a command ('command injection') in Fortinet FortiExtender version 7.0.1 and below, 4.2.3 and below, 4.1.7 and below allows an authenticated attacker to execute privileged shell commands

This month

HIGH 7.8UPGRADE

CVE-2021-41016 is a high-severity flaw (CVSS 7.8) affecting fortiextender firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A improper neutralization of special elements used in a command ('command injection') in Fortinet FortiExtender version 7.0.1 and below, 4.2.3 and below, 4.1.7 and below allows an authenticated attacker to execute privileged shell commands via CLI commands including special characters

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	7.8 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	1.1% (top 36%)
CISA exploited list	No
Weakness	CWE-78
Published	2022-02-02
Last modified	2026-06-17

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

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2022-02-02 11:15 UTCPublished CVE record published
2026-06-17 04:07 UTCUpdated Record last modified

fortinet fortiextender firmware UPGRADE

Affected: >= 4.1.1 and < 4.1.8 · >= 4.2.0 and < 4.2.4 · >= 7.0.0 and < 7.0.2

Fixed in: 4.1.8, 4.2.4, 7.0.2

Safe to downgrade to: a release before 4.1.1

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.

Verify at the official source NVD · CVE Program · 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-2021-41016?

fortiextender firmware: upgrade to 4.1.8, 4.2.4, 7.0.2. Exact commands for each OS are on this page.

Is CVE-2021-41016 being exploited?

CVE-2021-41016 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-41016 affect?

CVE-2021-41016 affects fortiextender firmware. Severity is high (CVSS 7.8). A improper neutralization of special elements used in a command ('command injection') in Fortinet FortiExtender version 7.0.1 and below, 4.2.3 and below, 4.1.7 and below allows an authenticated attacker to execute privileged shell commands

How urgent is CVE-2021-41016?

Priority 43/100. High severity

Software pages

Fortinet vulnerabilities

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References

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