Signedness error in ccid_serial.c in libccid in the USB Chip/Smart Card Interface Devices (CCID) driver as used in pcscd in PCSC-Lite 1.5.3 and possibly other products allows physically proximate attackers to execute arbitrary code via a smart card with a crafted serial number that causes a negative value to be used in a memcpy operation which triggers a buffer overflow. NOTE: some sources refer to this issue as an integer overflow.