Buffer overflows in mpg321 before 0.2.9 allows local and possibly remote attackers to execute arbitrary code via a long URL to (1) a command line option, (2) an HTTP request, or (3) an FTP request.
mpg321 0.2.10 allows remote attackers to overwrite memory and possibly execute arbitrary code via an mp3 file that passes certain strings to the printf function, possibly triggering a format string vulnerability.