CVE-2021-42756
Multiple stack-based buffer overflow vulnerabilities [CWE-121] in the proxy daemon of FortiWeb 5.x all versions, 6.0.7 and below, 6.1.2 and below, 6.2.6 and below, 6.3.16 and below, 6.4 all versions may allow an unauthenticated remote attacker to achieve arbitrary code execution via specifically crafted HTTP requests.
Key facts
- CVSS score
- 9.8 (v3.1)
- Severity
- CRITICAL
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H- Weakness (CWE)
- CWE-121
- EPSS score
- 35.0% (98th percentile)
- In CISA KEV
- No
- In EU EUVD
- Yes (EUVD-2021-29714)
- Published
- February 16, 2023
- NVD last modified
- June 17, 2026
- Status
- Modified
EU Vulnerability Database (EUVD)
This vulnerability is also tracked by ENISA as EUVD-2021-29714 in the EU Vulnerability Database. Last updated in EUVD on October 23, 2024.
View on the EU Vulnerability DatabaseAffected products
- fortinet / fortiweb
Certified products that may be affected
3 FIPS 140 or Common Criteria certified products, from automated matching by sec-certs.org.
- FortiWeb 5.6 - Fortinet, Inc. - FIPS 140 3103 - historical
- FortiWeb-3000E/4000E - Fortinet, Inc. - FIPS 140 3104 - historical
- Fortinet Fortiweb 5.6 - Fortinet, Inc. - Common Criteria 383-4-425 - archived
References
- https://fortiguard.com/psirt/FG-IR-21-186(Vendor Advisory)
Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS
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