CVE-2021-36167

MEDIUMNVD 4.35.3▲

4.3

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.

CVSS v3: 4.3
EG Score: 5.3(medium)
EPSS: 32.0%
KEV: Not listed

Published

December 9, 2021

Last Modified

November 21, 2024

References (2)

psirt@fortinethttps://fortiguard.com/advisory/FG-IR-20-127
af854a3a-2127-422b-91ae-364da2661108https://fortiguard.com/advisory/FG-IR-20-127

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

CWE-863Incorrect Authorization

Data Freshness Timeline

(refreshed 12× in last 7d / 20× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

2026-06-08 14:15 UTCEPSS rescore
2026-06-08 14:15 UTCEPSS rescore
2026-06-07 15:23 UTCEPSS rescore
2026-06-07 15:23 UTCEPSS rescore
2026-06-06 13:46 UTCEPSS rescore
2026-06-06 13:46 UTCEPSS rescore
2026-06-06 13:46 UTCEPSS rescore
2026-06-05 22:45 UTCEPSS rescore
2026-06-05 06:09 UTCEPSS rescore
2026-06-05 06:09 UTCEPSS rescore
2026-06-04 13:10 UTCEPSS rescore
2026-06-04 13:10 UTCEPSS rescore
2026-06-02 20:11 UTCEPSS rescore
2026-06-02 20:11 UTCEPSS rescore
2026-06-01 13:50 UTCEPSS rescore
2026-06-01 13:50 UTCEPSS rescore
2026-05-31 22:29 UTCEPSS rescore
2026-05-31 22:29 UTCEPSS rescore
2026-05-31 00:15 UTCEPSS rescore
2026-05-31 00:15 UTCEPSS rescore

Frequently asked(5)

What is CVE-2021-36167?

CVE-2021-36167 is a medium vulnerability published on December 9, 2021. 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.

When was CVE-2021-36167 disclosed?

CVE-2021-36167 was first published in the National Vulnerability Database on December 9, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2021-36167 actively exploited?

CVE-2021-36167 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 32.0% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2021-36167?

CVE-2021-36167 has a CVSS v3 base score of 4.3 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 5.3.

How do I remediate CVE-2021-36167?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-36167, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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CVE-2021-36167

📅 Published

🔄 Last Modified

🔗 References (2)

Weakness Classification(1)

Data Freshness Timeline

❓ Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2021-36167?

🔗 Related CVEs(same CWE)

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Published

Last Modified

References (2)

Frequently asked(5)

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