How severe is CVE-2021-36180?

CVE-2021-36180 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability high.

Is CVE-2021-36180 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (66th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-36180?

CVE-2021-36180 primarily affects Fortinet Fortiweb. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-36180?

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-2021-36180 published?

CVE-2021-36180 was published on 2021-12-08 and last updated on 2026-06-17.

CVE-2021-36180

CVE-2021-36180 is a high-severity vulnerability in Fortinet Fortiweb with a CVSS 3.x base score of 8.1. 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 8.1)
CVSS v2: 6.5
EPSS exploit prediction: 1% (66th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-78
Affected product: Fortinet Fortiweb
Published: 2021-12-08
Last modified: 2026-06-17

Description

Multiple improper neutralization of special elements used in a command vulnerabilities [CWE-77] in FortiWeb management interface 6.4.1 and below, 6.3.15 and below, 6.2.5 and below may allow an authenticated attacker to execute unauthorized code or commands via crafted parameters of HTTP requests.

Frequently asked questions

What is CVE-2021-36180?: Multiple improper neutralization of special elements used in a command vulnerabilities [CWE-77] in FortiWeb management interface 6.4.1 and below, 6.3.15 and below, 6.2.5 and below may allow an authenticated attacker to execute unauthorized code or commands via crafted parameters of HTTP requests.
How severe is CVE-2021-36180?: CVE-2021-36180 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability high.
Is CVE-2021-36180 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (66th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-36180?: CVE-2021-36180 primarily affects Fortinet Fortiweb. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-36180?: 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-2021-36180 published?: CVE-2021-36180 was published on 2021-12-08 and last updated on 2026-06-17.

References

https://fortiguard.com/advisory/FG-IR-21-120

Affected products (7)

cpe:2.3:a:fortinet:fortiweb:*:*:*:*:*:*:*:*
cpe:2.3:a:fortinet:fortiweb:5.9.0:*:*:*:*:*:*:*
cpe:2.3:a:fortinet:fortiweb:5.9.1:*:*:*:*:*:*:*
cpe:2.3:a:fortinet:fortiweb:6.1.0:*:*:*:*:*:*:*
cpe:2.3:a:fortinet:fortiweb:6.1.1:*:*:*:*:*:*:*
cpe:2.3:a:fortinet:fortiweb:6.4.0:*:*:*:*:*:*:*
cpe:2.3:a:fortinet:fortiweb:6.4.1:*:*:*:*:*:*:*

More vulnerabilities in Fortinet Fortiweb

CVE-2026-26035 — Critical (CVSS 9.8): An Improper Authentication vulnerability [CWE-287] vulnerability in Fortinet FortiWeb 8.0.0 through 8.0.2, FortiWeb…
CVE-2026-24858 — Critical (CVSS 9.8): An Authentication Bypass Using an Alternate Path or Channel vulnerability [CWE-288] vulnerability in Fortinet…
CVE-2025-59719 — Critical (CVSS 9.8): An improper verification of cryptographic signature vulnerability in Fortinet FortiWeb 8.0.0, FortiWeb 7.6.0 through…
CVE-2025-64446 — Critical (CVSS 9.8): A relative path traversal vulnerability in Fortinet FortiWeb 8.0.0 through 8.0.1, FortiWeb 7.6.0 through 7.6.4,…
CVE-2025-25257 — Critical (CVSS 9.8): An improper neutralization of special elements used in an SQL command ('SQL Injection') vulnerability [CWE-89]…
CVE-2023-25610 — Critical (CVSS 9.8): A buffer underwrite ('buffer underflow') vulnerability in the administrative interface of Fortinet FortiOS version…

All CVEs affecting Fortinet Fortiweb →

Other CWE-78 (OS Command Injection) vulnerabilities

CVE-2026-100382 — Critical (CVSS 10.0): Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') vulnerability in Wikimedia…
CVE-2026-77521 — Critical (CVSS 10.0): MaxKB is an open-source AI assistant for enterprise. Prior to version 2.10.5-lts, assistants with a tool, MCP tool,…
CVE-2026-82004 — Critical (CVSS 10.0): Adobe Campaign Classic (ACC) is affected by an Improper Neutralization of Special Elements used in an OS Command ('OS…
CVE-2026-76197 — Critical (CVSS 10.0): Adobe Campaign Classic (ACC) is affected by an Improper Neutralization of Special Elements used in an OS Command ('OS…
CVE-2026-76195 — Critical (CVSS 10.0): Adobe Campaign Classic (ACC) is affected by an Improper Neutralization of Special Elements used in an OS Command ('OS…
CVE-2026-19188 — Critical (CVSS 10.0): A critical OS command injection vulnerability has been identified in the Haiwell IoT Cloud HMI Gateway product. The…

Browse all CWE-78 (OS Command Injection) vulnerabilities →