A stack-based buffer overflow vulnerability exists in ActFax Server version 4.32, specifically in the "Import Users from File" functionality of the client interface. The application fails to properly validate the length of tab-delimited fields in .exp files, leading to unsafe usage of strcpy() during CSV parsing. An attacker can exploit this vulnerability by crafting a malicious .exp file and importing it using the default character set "ECMA-94 / Latin 1 (ISO 8859)". Successful exploitation may result in arbitrary code execution, leading to full system compromise. User interaction is required to trigger the vulnerability.