CVE-1999-0667

CVE-1999-0667 describes a fundamental vulnerability within the ARP protocol itself, affecting all implementations. An attacker can spoof ARP replies to poison network device caches, leading to IP address spoofing or denial-of-service attacks. With a CVSS score of 10.0 (AV:N/AC:L/Au:N/C:C/I:C/A:C), this vulnerability is critical, indicating it can be exploited remotely with low complexity and result in complete compromise of confidentiality, integrity, and availability. While not listed on the KEV catalog, exploit modules like Metasploit's ARP Spoof exist, and there is ongoing community discussion about its nature as an exploit.