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.
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.