Stack-based buffer overflow in the ATRDecodeAtr function in the Answer-to-Reset (ATR) Handler (atrhandler.c) for pcscd in PCSC-Lite 1.5.3, and possibly other 1.5.x and 1.6.x versions, allows physically proximate attackers to cause a denial of service (crash) and possibly execute arbitrary code via a smart card with an ATR message containing a long attribute value.