CVE-2004-2375

CVE-2004-2375 describes a buffer overflow vulnerability in the POP3 server component of 1st Class Mail Server 4.0. This flaw allows remote, unauthenticated attackers to trigger a denial of service (crash) and potentially execute arbitrary code by sending a specially crafted APOP USER command with an excessively long digest parameter. With a CVSS score of 7.5, it is considered highly severe due to its network-based attack vector, low attack complexity, and potential for full compromise (confidentiality, integrity, availability). While not listed on the KEV catalog, a proof-of-concept exploit is publicly available on ExploitDB, though there is no evidence of widespread active exploitation or significant community discussion.