Today's world totally work through important asset i.e. information and there should protective shield to protect such asset with good performance. Therefore Security issue is the important and elicited topic among IT professionals. The Buffer Overflow which is one of the most frequently occurring security vulnerabilities on network. Buffer Overflow occurs while writing data to a buffer and it overruns the buffer's threshold and overwrites it to neighboring memory. This paper focused on finding and detection of buffer overflow occurs during transmission of jpg and gif file format over network. The signature and signature free detection mechanism is implemented for detection of buffer overflow during transmission. First the signature based detection finds a particular signature after the signature free technology is implanted for testing the buffer overflow. The discussion is concluded with some thoughts on buffer overflow detection in general, and directions for the analysis and remediation of buffer over?ow detection for gif and jpg file format.