Vulnerability identifier: #VU64930

Vulnerability risk: Medium

CVSSv3.1: 5.7 [CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-42755

CWE-ID: CWE-190

Exploitation vector: Local network

Exploit availability: No

Vulnerable software:
FortiOS
Operating systems & Components / Operating system

Vendor: Fortinet, Inc

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to integer overflow within the dhcpd deamon. A remote non-authenticated attacker on the local network can send specially crafted traffic to the affected system, trigger an integer overflow and perform a denial of service (DoS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

FortiOS: 7.0.0 - 7.0.2, 6.2.0 - 6.2.11, 6.0.0 - 6.0.14, 6.4.0 - 6.4.8

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External links
http://fortiguard.fortinet.com/psirt/FG-IR-21-155

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the local network (LAN).

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.