What’s Vulnerable › Vulnerabilities

CVE-2021-42755

• Severity: medium (CVSS 4.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2022-07-18 · updated 2026-06-17
• Weakness: CWE-190

Description

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.

Affected products

• Fortinet FortiOS (FortiGate): 5.4.0, 5.4.1, 5.4.2, 5.4.3, 5.4.4, 5.4.5 (+60)
• Fortinet FortiProxy: from 1.0.0 through 1.0.7; from 1.1.0 through 1.1.6; from 1.2.0 through 1.2.13; from 2.0.0 through 2.0.6; 7.0.0
• Fortinet FortiRecorder: 6.0.0, 6.0.1, 6.0.2, 6.0.3, 6.0.4, 6.0.5 (+8)
• Fortinet FortiSwitch: from 6.0.0 through 6.0.7; from 6.2.0 through 6.2.7; from 6.4.0 through 6.4.9; from 7.0.0 through 7.0.2
• Fortinet FortiVoice: 5.3.0, 5.3.1, 5.3.2, 5.3.3, 5.3.4, 5.3.5 (+35)

References

• https://fortiguard.com/psirt/FG-IR-21-155
• https://fortiguard.com/psirt/FG-IR-21-155

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