BusyBox wget: crafted FTP file size enables heap overflow and code execution

A flaw was found in BusyBox. When resuming a download over File Transfer Protocol (FTP), the wget utility fails to verify that the resume offset does not exceed the file size reported by the server, resulting in an integer calculation error. A malicious FTP server or an on-path network attacker can exploit this issue by returning crafted file size metadata, triggering a heap-based buffer overflow with attacker-controlled data. Successful exploitation may allow an attacker to execute arbitrary code or crash the application, resulting in a denial of service (DoS).