xine-lib 1.1.12, and other 1.1.15 and earlier versions, does not properly handle (a) negative and (b) zero values during unspecified read function calls in input_file.c, input_net.c, input_smb.c, and input_http.c, which allows remote attackers to cause a denial of service (crash) or possibly execute arbitrary code via vectors such as (1) a file or (2) an HTTP response, which triggers consequences such as out-of-bounds reads and heap-based buffer overflows.