hMailServer is an open-source Windows mail server supporting SMTP, POP3, and IMAP. Over the years, multiple vulnerabilities affecting hMailServer have been disclosed (buffer overflows, authentication bypasses, improper input validation, and unsafe deserialization). Attack code and proof-of-concept (PoC) implementations have appeared in public repositories (including GitHub) after disclosure. This write-up outlines typical classes of hMailServer vulnerabilities, how they were exploited, indicators of compromise (IOCs), and actionable defensive measures.
When searching GitHub for these exploits, use the following dorks for the best results: CVE-2024-27732 poc hMailServer RCE exploit hmailserver privilege escalation script Summary Table for Write-ups Vulnerability Version Affected Key Exploit Vector CVE-2024-27732 < 5.7.3-B2646 .NET Deserialization via COM CVE-2019-14238 Malicious Event Scripts (SYSTEM) Insecure Config hMailServer.INI password disclosure hmailserver exploit github
: While technically a Microsoft Outlook vulnerability, hMailServer is often used as the backend mail server in labs to demonstrate this "critical" bug. Attackers can use scripts like Xaitax's PoC to bypass SPF/DKIM/DMARC checks and send malicious emails that leak NTLM hashes or achieve remote code execution. hMailServer is an open-source Windows mail server supporting
HMailServer is a free, open-source mail server software written in C++ and designed to be highly customizable. It supports various features such as SMTP, POP3, and IMAP protocols, making it a versatile email solution. The software has been widely used by individuals, small businesses, and organizations due to its flexibility and cost-effectiveness. HMailServer is a free, open-source mail server software