How severe is CVE-2021-41018?

CVE-2021-41018 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-41018 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (88th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-41018?

CVE-2021-41018 affects Fortinet Fortiweb. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-41018?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-41018 published?

CVE-2021-41018 was published on 2022-02-02 and last updated on 2026-06-17.

CVE-2021-41018

CVE-2021-41018 is a high-severity vulnerability in Fortinet Fortiweb with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-78.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 9.0
EPSS exploit prediction: 3% (88th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-78
Affected product: Fortinet Fortiweb
Published: 2022-02-02
Last modified: 2026-06-17

Description

A improper neutralization of special elements used in an os command ('os command injection') in Fortinet FortiWeb version 6.4.1 and below, 6.3.15 and below allows attacker to execute unauthorized code or commands via crafted HTTP requests.

Frequently asked questions

What is CVE-2021-41018?: A improper neutralization of special elements used in an os command ('os command injection') in Fortinet FortiWeb version 6.4.1 and below, 6.3.15 and below allows attacker to execute unauthorized code or commands via crafted HTTP requests.
How severe is CVE-2021-41018?: CVE-2021-41018 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-41018 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (88th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-41018?: CVE-2021-41018 affects Fortinet Fortiweb. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-41018?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-41018 published?: CVE-2021-41018 was published on 2022-02-02 and last updated on 2026-06-17.

References

https://fortiguard.com/advisory/FG-IR-21-166

Affected products (1)

cpe:2.3:a:fortinet:fortiweb:*:*:*:*:*:*:*:*

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