How severe is CVE-2021-36167?

CVE-2021-36167 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.

Is CVE-2021-36167 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-36167?

CVE-2021-36167 primarily affects Fortinet Forticlient. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-36167?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-36167 published?

CVE-2021-36167 was published on 2021-12-09 and last updated on 2026-06-17.

CVE-2021-36167

CVE-2021-36167 is a medium-severity vulnerability in Fortinet Forticlient with a CVSS 3.x base score of 4.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
CVSS v2: 5.0
EPSS exploit prediction: 1% (43rd percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Fortinet Forticlient
Published: 2021-12-09
Last modified: 2026-06-17

Description

An improper authorization vulnerabiltiy [CWE-285] in FortiClient Windows versions 7.0.0 and 6.4.6 and below and 6.2.8 and below may allow an unauthenticated attacker to bypass the webfilter control via modifying the session-id paramater.

Frequently asked questions

What is CVE-2021-36167?: An improper authorization vulnerabiltiy [CWE-285] in FortiClient Windows versions 7.0.0 and 6.4.6 and below and 6.2.8 and below may allow an unauthenticated attacker to bypass the webfilter control via modifying the session-id paramater.
How severe is CVE-2021-36167?: CVE-2021-36167 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.
Is CVE-2021-36167 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-36167?: CVE-2021-36167 primarily affects Fortinet Forticlient. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-36167?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-36167 published?: CVE-2021-36167 was published on 2021-12-09 and last updated on 2026-06-17.

References

https://fortiguard.com/advisory/FG-IR-20-127

Affected products (3)

cpe:2.3:a:fortinet:forticlient:*:*:*:*:*:windows:*:*
cpe:2.3:a:fortinet:forticlient:6.2.7:*:*:*:*:windows:*:*
cpe:2.3:a:fortinet:forticlient:7.0.0:*:*:*:*:windows:*:*

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