Heap-based buffer overflow in smtp_in.c for Exim 3 (exim3) before 3.36 and Exim 4 (exim4) before 4.21 may allow remote attackers to execute arbitrary code via an invalid (1) HELO or (2) EHLO argument with a large number of spaces followed by a NULL character and a newline, which is not properly trimmed before the "(no argument given)" string is appended to the buffer.
Format string vulnerability in daemon.c for Exim 4.x through 4.10, and 3.x through 3.36, allows exim administrative users to execute arbitrary code by modifying the pid_file_path value.