Is CVE-2021-42755 being actively exploited?

CVE-2021-42755 is not currently listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

What is the CVSS score for CVE-2021-42755?

CVE-2021-42755 has a CVSS 3.1 base score of 4.3 (MEDIUM).

CVE-2021-42755

MEDIUM · CVSS 4.3EPSS 0.4%EU EUVD

An integer overflow / wraparound vulnerability [CWE-190] in FortiSwitch 7.0.2 and below, 6.4.9 and below, 6.2.x, 6.0.x; FortiRecorder 6.4.2 and below, 6.0.10 and below; FortiOS 7.0.2 and below, 6.4.8 and below, 6.2.10 and below, 6.0.x; FortiProxy 7.0.0, 2.0.6 and below, 1.2.x, 1.1.x, 1.0.x; FortiVoiceEnterprise 6.4.3 and below, 6.0.10 and below dhcpd daemon may allow an unauthenticated and network adjacent attacker to crash the dhcpd deamon, resulting in potential denial of service.

Key facts

CVSS score: 4.3 (v3.1)
Severity: MEDIUM
CVSS vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Weakness (CWE): CWE-190
EPSS score: 0.4% (33th percentile)
In CISA KEV: No
In EU EUVD: Yes (EUVD-2021-29713)
Published: July 18, 2022
NVD last modified: June 17, 2026
Status: Modified

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2021-29713 in the EU Vulnerability Database. Last updated in EUVD on August 4, 2024.

View on the EU Vulnerability Database

Affected products

fortinet / fortios
fortinet / fortios
fortinet / fortios
fortinet / fortios
fortinet / fortios
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fortinet / fortios
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fortinet / fortios
fortinet / fortios
fortinet / fortios
fortinet / fortios

and 74 more…

Certified products that may be affected

4 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

References

https://fortiguard.com/psirt/FG-IR-21-155(Patch, Vendor Advisory)

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

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