Is CVE-2021-42757 being actively exploited?

CVE-2021-42757 is not currently listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

What is the CVSS score for CVE-2021-42757?

CVE-2021-42757 has a CVSS 3.1 base score of 6.7 (MEDIUM).

CVE-2021-42757

MEDIUM · CVSS 6.7EPSS 0.5%EU EUVD

A buffer overflow [CWE-121] in the TFTP client library of FortiOS before 6.4.7 and FortiOS 7.0.0 through 7.0.2, may allow an authenticated local attacker to achieve arbitrary code execution via specially crafted command line arguments.

Key facts

CVSS score: 6.7 (v3.1)
Severity: MEDIUM
CVSS vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-120
EPSS score: 0.5% (42th percentile)
In CISA KEV: No
In EU EUVD: Yes (EUVD-2021-29715)
Published: December 8, 2021
NVD last modified: June 17, 2026
Status: Modified

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2021-29715 in the EU Vulnerability Database. Last updated in EUVD on October 16, 2025.

View on the EU Vulnerability Database

Affected products

fortinet / fortiadc
fortinet / fortianalyzer
fortinet / fortimail
fortinet / fortimanager
fortinet / fortindr
fortinet / fortios
fortinet / fortios-6k7k
fortinet / fortios-6k7k
fortinet / fortios-6k7k
fortinet / fortiportal
fortinet / fortiproxy
fortinet / fortiproxy
fortinet / fortiproxy
fortinet / fortirecorder firmware
fortinet / fortiswitch
fortinet / fortivoice
fortinet / fortiweb
fortinet / fortiweb
fortinet / fortiweb

Certified products that may be affected

11 FIPS 140 or Common Criteria certified products, from automated matching by sec-certs.org.

FortiGate/FortiOS Version 6.2.7 - Fortinet, Inc. - Common Criteria 559-LSS - archived
FortiOS 5.6 - Fortinet, Inc. - FIPS 140 3639 - historical
FortiProxy-400E/2000E/4000E - Fortinet, Inc. - FIPS 140 3628 - historical
Fortinet FortiProxy v1.0 - Fortinet, Inc. - Common Criteria 383-4-475 - archived
FortiMail 6.0 - Fortinet, Inc. - FIPS 140 3380 - historical

See all 11 in the Security Certifications Explorer.

References

https://fortiguard.com/advisory/FG-IR-21-173(Vendor Advisory)

Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS

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