Multiple TCP/IP and ICMP implementations, when using Path MTU (PMTU) discovery (PMTUD), allow remote attackers to cause a denial of service (network throughput reduction for TCP connections) via forged ICMP ("Fragmentation Needed and Don't Fragment was Set") packets with a low next-hop MTU value, aka the "Path MTU discovery attack." NOTE: CVE-2004-0790, CVE-2004-0791, and CVE-2004-1060 have been SPLIT based on different attacks; CVE-2005-0065, CVE-2005-0066, CVE-2005-0067, and CVE-2005-0068 are related identifiers that are SPLIT based on the underlying vulnerability. While CVE normally SPLITs based on vulnerability, the attack-based identifiers exist due to the variety and number of affected implementations and solutions that address the attacks instead of the underlying vulnerabilities.