medium
4.3
CWE
190
Advisory Published
CVE Published
Updated
Advisory Published

CVE-2021-42755: Integer overflow in dhcpd daemon

First published: Tue Jul 05 2022(Updated: )

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.

Credit: psirt@fortinet.com

Affected SoftwareAffected VersionHow to fix
Fortinet FortiProxy>=1.0.0<=1.0.7
Fortinet FortiProxy>=1.1.0<=1.1.6
Fortinet FortiProxy>=1.2.0<=1.2.13
Fortinet FortiProxy>=2.0.0<=2.0.6
Fortinet FortiProxy=7.0.0
Fortinet FortiVoice Enterprise=5.3.0
Fortinet FortiVoice Enterprise=5.3.1
Fortinet FortiVoice Enterprise=5.3.2
Fortinet FortiVoice Enterprise=5.3.3
Fortinet FortiVoice Enterprise=5.3.4
Fortinet FortiVoice Enterprise=5.3.5
Fortinet FortiVoice Enterprise=5.3.6
Fortinet FortiVoice Enterprise=5.3.7
Fortinet FortiVoice Enterprise=5.3.8
Fortinet FortiVoice Enterprise=5.3.10
Fortinet FortiVoice Enterprise=5.3.11
Fortinet FortiVoice Enterprise=5.3.12
Fortinet FortiVoice Enterprise=5.3.13
Fortinet FortiVoice Enterprise=5.3.14
Fortinet FortiVoice Enterprise=5.3.15
Fortinet FortiVoice Enterprise=5.3.16
Fortinet FortiVoice Enterprise=5.3.17
Fortinet FortiVoice Enterprise=5.3.18
Fortinet FortiVoice Enterprise=5.3.19
Fortinet FortiVoice Enterprise=5.3.20
Fortinet FortiVoice Enterprise=5.3.21
Fortinet FortiVoice Enterprise=5.3.22
Fortinet FortiVoice Enterprise=5.3.23
Fortinet FortiVoice Enterprise=5.3.24
Fortinet FortiVoice Enterprise=5.3.25
Fortinet FortiVoice Enterprise=5.3.26
Fortinet FortiVoice Enterprise=6.0.0
Fortinet FortiVoice Enterprise=6.0.1
Fortinet FortiVoice Enterprise=6.0.2
Fortinet FortiVoice Enterprise=6.0.3
Fortinet FortiVoice Enterprise=6.0.4
Fortinet FortiVoice Enterprise=6.0.5
Fortinet FortiVoice Enterprise=6.0.6
Fortinet FortiVoice Enterprise=6.0.7
Fortinet FortiVoice Enterprise=6.0.8
Fortinet FortiVoice Enterprise=6.0.9
Fortinet FortiVoice Enterprise=6.0.10
Fortinet FortiVoice Enterprise=6.4.0
Fortinet FortiVoice Enterprise=6.4.1
Fortinet FortiVoice Enterprise=6.4.2
Fortinet FortiVoice Enterprise=6.4.3
Fortinet FortiOS IPS Engine=5.4.0
Fortinet FortiOS IPS Engine=5.4.1
Fortinet FortiOS IPS Engine=5.4.2
Fortinet FortiOS IPS Engine=5.4.3
Fortinet FortiOS IPS Engine=5.4.4
Fortinet FortiOS IPS Engine=5.4.5
Fortinet FortiOS IPS Engine=5.4.6
Fortinet FortiOS IPS Engine=5.4.7
Fortinet FortiOS IPS Engine=5.4.8
Fortinet FortiOS IPS Engine=5.4.9
Fortinet FortiOS IPS Engine=5.4.10
Fortinet FortiOS IPS Engine=5.4.11
Fortinet FortiOS IPS Engine=5.4.12
Fortinet FortiOS IPS Engine=5.4.13
Fortinet FortiOS IPS Engine=5.6.0
Fortinet FortiOS IPS Engine=5.6.1
Fortinet FortiOS IPS Engine=5.6.2
Fortinet FortiOS IPS Engine=5.6.3
Fortinet FortiOS IPS Engine=5.6.4
Fortinet FortiOS IPS Engine=5.6.5
Fortinet FortiOS IPS Engine=5.6.6
Fortinet FortiOS IPS Engine=5.6.7
Fortinet FortiOS IPS Engine=5.6.8
Fortinet FortiOS IPS Engine=5.6.9
Fortinet FortiOS IPS Engine=5.6.10
Fortinet FortiOS IPS Engine=5.6.11
Fortinet FortiOS IPS Engine=5.6.12
Fortinet FortiOS IPS Engine=5.6.13
Fortinet FortiOS IPS Engine=5.6.14
Fortinet FortiOS IPS Engine=6.0.0
Fortinet FortiOS IPS Engine=6.0.1
Fortinet FortiOS IPS Engine=6.0.2
Fortinet FortiOS IPS Engine=6.0.3
Fortinet FortiOS IPS Engine=6.0.4
Fortinet FortiOS IPS Engine=6.0.5
Fortinet FortiOS IPS Engine=6.0.6
Fortinet FortiOS IPS Engine=6.0.7
Fortinet FortiOS IPS Engine=6.0.8
Fortinet FortiOS IPS Engine=6.0.9
Fortinet FortiOS IPS Engine=6.0.10
Fortinet FortiOS IPS Engine=6.0.11
Fortinet FortiOS IPS Engine=6.0.12
Fortinet FortiOS IPS Engine=6.0.13
Fortinet FortiOS IPS Engine=6.0.14
Fortinet FortiOS IPS Engine=6.2.0
Fortinet FortiOS IPS Engine=6.2.1
Fortinet FortiOS IPS Engine=6.2.2
Fortinet FortiOS IPS Engine=6.2.3
Fortinet FortiOS IPS Engine=6.2.4
Fortinet FortiOS IPS Engine=6.2.5
Fortinet FortiOS IPS Engine=6.2.6
Fortinet FortiOS IPS Engine=6.2.7
Fortinet FortiOS IPS Engine=6.2.8
Fortinet FortiOS IPS Engine=6.2.9
Fortinet FortiOS IPS Engine=6.2.10
Fortinet FortiOS IPS Engine=6.4.0
Fortinet FortiOS IPS Engine=6.4.1
Fortinet FortiOS IPS Engine=6.4.2
Fortinet FortiOS IPS Engine=6.4.3
Fortinet FortiOS IPS Engine=6.4.4
Fortinet FortiOS IPS Engine=6.4.5
Fortinet FortiOS IPS Engine=6.4.6
Fortinet FortiOS IPS Engine=6.4.7
Fortinet FortiOS IPS Engine=7.0.0
Fortinet FortiOS IPS Engine=7.0.1
Fortinet FortiOS IPS Engine=7.0.2
Fortinet FortiRecorder Firmware=6.0.0
Fortinet FortiRecorder Firmware=6.0.1
Fortinet FortiRecorder Firmware=6.0.2
Fortinet FortiRecorder Firmware=6.0.3
Fortinet FortiRecorder Firmware=6.0.4
Fortinet FortiRecorder Firmware=6.0.5
Fortinet FortiRecorder Firmware=6.0.6
Fortinet FortiRecorder Firmware=6.0.7
Fortinet FortiRecorder Firmware=6.0.8
Fortinet FortiRecorder Firmware=6.0.9
Fortinet FortiRecorder Firmware=6.0.10
Fortinet FortiRecorder Firmware=6.4.0
Fortinet FortiRecorder Firmware=6.4.1
Fortinet FortiRecorder Firmware=6.4.2
Fortinet FortiSwitch>=6.0.0<=6.0.7
Fortinet FortiSwitch>=6.2.0<=6.2.7
Fortinet FortiSwitch>=6.4.0<=6.4.9
Fortinet FortiSwitch>=7.0.0<=7.0.2
Fortinet FortiVoice Enterprise=5.3.0
Fortinet FortiVoice Enterprise=5.3.1
Fortinet FortiVoice Enterprise=5.3.2
Fortinet FortiVoice Enterprise=5.3.3
Fortinet FortiVoice Enterprise=5.3.4
Fortinet FortiVoice Enterprise=5.3.5
Fortinet FortiVoice Enterprise=5.3.6
Fortinet FortiVoice Enterprise=5.3.7
Fortinet FortiVoice Enterprise=5.3.8
Fortinet FortiVoice Enterprise=5.3.10
Fortinet FortiVoice Enterprise=5.3.11
Fortinet FortiVoice Enterprise=5.3.12
Fortinet FortiVoice Enterprise=5.3.13
Fortinet FortiVoice Enterprise=5.3.14
Fortinet FortiVoice Enterprise=5.3.15
Fortinet FortiVoice Enterprise=5.3.16
Fortinet FortiVoice Enterprise=5.3.17
Fortinet FortiVoice Enterprise=5.3.18
Fortinet FortiVoice Enterprise=5.3.19
Fortinet FortiVoice Enterprise=5.3.20
Fortinet FortiVoice Enterprise=5.3.21
Fortinet FortiVoice Enterprise=5.3.22
Fortinet FortiVoice Enterprise=5.3.23
Fortinet FortiVoice Enterprise=5.3.24
Fortinet FortiVoice Enterprise=5.3.25
Fortinet FortiVoice Enterprise=5.3.26
Fortinet FortiVoice Enterprise=6.0.0
Fortinet FortiVoice Enterprise=6.0.1
Fortinet FortiVoice Enterprise=6.0.2
Fortinet FortiVoice Enterprise=6.0.3
Fortinet FortiVoice Enterprise=6.0.4
Fortinet FortiVoice Enterprise=6.0.5
Fortinet FortiVoice Enterprise=6.0.6
Fortinet FortiVoice Enterprise=6.0.7
Fortinet FortiVoice Enterprise=6.0.8
Fortinet FortiVoice Enterprise=6.0.9
Fortinet FortiVoice Enterprise=6.0.10
Fortinet FortiVoice Enterprise=6.4.0
Fortinet FortiVoice Enterprise=6.4.1
Fortinet FortiVoice Enterprise=6.4.2
Fortinet FortiVoice Enterprise=6.4.3

Remedy

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

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Reference Links

Frequently Asked Questions

  • What is the severity of CVE-2021-42755?

    CVE-2021-42755 has been classified with a severity level of high due to the potential for remote code execution resulting from the integer overflow vulnerability.

  • How do I fix CVE-2021-42755?

    To resolve CVE-2021-42755, it is recommended to upgrade your FortiSwitch, FortiRecorder, or FortiOS to the latest versions provided by Fortinet.

  • What systems are affected by CVE-2021-42755?

    CVE-2021-42755 affects FortiSwitch versions 7.0.2 and below, FortiRecorder versions 6.4.2 and below, and multiple versions of FortiOS and FortiProxy.

  • Can CVE-2021-42755 be exploited remotely?

    Yes, CVE-2021-42755 can be exploited remotely, allowing attackers to potentially execute arbitrary code on the affected devices.

  • What precautions should I take regarding CVE-2021-42755?

    In addition to applying security updates, consider monitoring network traffic for unusual activities and ensuring proper firewall rules are in place to mitigate risks.

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