diff -ru pcsc-lite-1.4.102.orig//src/winscard_svc.c pcsc-lite-1.4.102/src/winscard_svc.c
--- pcsc-lite-1.4.102.orig//src/winscard_svc.c	2008-06-27 05:31:39.000000000 +0200
+++ pcsc-lite-1.4.102/src/winscard_svc.c	2010-05-26 15:04:04.000000000 +0200
@@ -385,6 +385,14 @@
 		dwProtocol = stStr->pdwProtocol;
 		cbAtrLen = stStr->pcbAtrLen;
 
+		/* avoids buffer overflow */
+		if ((cchReaderLen > sizeof(stStr->mszReaderNames))
+			|| (cbAtrLen > sizeof(stStr->pbAtr)))
+		{
+			stStr->rv = SCARD_E_INSUFFICIENT_BUFFER ;
+			break;
+		}
+
 		stStr->rv = SCardStatus(stStr->hCard, stStr->mszReaderNames,
 			&cchReaderLen, &dwState,
 			&dwProtocol, stStr->pbAtr, &cbAtrLen);
@@ -400,6 +408,14 @@
 		rv = MSGCheckHandleAssociation(trStr->hCard, dwContextIndex);
 		if (rv != 0) return rv;
 
+		/* avoids buffer overflow */
+		if ((trStr->pcbRecvLength > sizeof(trStr->pbRecvBuffer))
+			|| (trStr->cbSendLength > sizeof(trStr->pbSendBuffer)))
+		{
+			trStr->rv = SCARD_E_INSUFFICIENT_BUFFER ;
+			break;
+		}
+
 		ioSendPci.dwProtocol = trStr->pioSendPciProtocol;
 		ioSendPci.cbPciLength = trStr->pioSendPciLength;
 		ioRecvPci.dwProtocol = trStr->pioRecvPciProtocol;
@@ -424,6 +440,14 @@
 		rv = MSGCheckHandleAssociation(ctStr->hCard, dwContextIndex);
 		if (rv != 0) return rv;
 
+		/* avoids buffer overflow */
+		if ((ctStr->cbRecvLength > sizeof(ctStr->cbRecvLength))
+			|| (ctStr->cbSendLength > sizeof(ctStr->pbSendBuffer)))
+		{
+			ctStr->rv = SCARD_E_INSUFFICIENT_BUFFER;
+			break;
+		}
+
 		dwBytesReturned = ctStr->dwBytesReturned;
 
 		ctStr->rv = SCardControl(ctStr->hCard, ctStr->dwControlCode,
@@ -440,6 +464,13 @@
 		rv = MSGCheckHandleAssociation(gsStr->hCard, dwContextIndex);
 		if (rv != 0) return rv;
 
+		/* avoids buffer overflow */
+		if (gsStr->cbAttrLen > sizeof(gsStr->pbAttr))
+		{
+			gsStr->rv = SCARD_E_INSUFFICIENT_BUFFER ;
+			break;
+		}
+
 		cbAttrLen = gsStr->cbAttrLen;
 
 		gsStr->rv = SCardGetAttrib(gsStr->hCard, gsStr->dwAttrId,
@@ -453,6 +484,14 @@
 		gsStr = ((getset_struct *) msgStruct->data);
 		rv = MSGCheckHandleAssociation(gsStr->hCard, dwContextIndex);
 		if (rv != 0) return rv;
+
+		/* avoids buffer overflow */
+		if (gsStr->cbAttrLen <= sizeof(gsStr->pbAttr))
+		{
+			gsStr->rv = SCARD_E_INSUFFICIENT_BUFFER ;
+			break;
+		}
+
 		gsStr->rv = SCardSetAttrib(gsStr->hCard, gsStr->dwAttrId,
 			gsStr->pbAttr, gsStr->cbAttrLen);
 		break;
@@ -467,6 +506,15 @@
 			rv = MSGCheckHandleAssociation(treStr->hCard, dwContextIndex);
 			if (rv != 0) return rv;
 
+			/* avoids buffer overflow */
+			if ((treStr->size > sizeof(pbSendBuffer))
+				|| (treStr->cbSendLength > sizeof(pbSendBuffer))
+				|| (treStr->pcbRecvLength > sizeof(pbRecvBuffer)))
+			{
+				treStr->rv = SCARD_E_INSUFFICIENT_BUFFER;
+				break;
+			}
+
 			/* on more block to read? */
 			if (treStr->size > PCSCLITE_MAX_MESSAGE_SIZE)
 			{
@@ -548,6 +596,15 @@
 			rv = MSGCheckHandleAssociation(cteStr->hCard, dwContextIndex);
 			if (rv != 0) return rv;
 
+			/* avoids buffer overflow */
+			if ((cteStr->size > sizeof(pbSendBuffer))
+				|| (cteStr->cbSendLength > sizeof(pbSendBuffer))
+				|| (cteStr->cbRecvLength > sizeof(pbRecvBuffer)))
+			{
+				cteStr->rv = SCARD_E_INSUFFICIENT_BUFFER;
+				break;
+			}
+
 			/* on more block to read? */
 			if (cteStr->size > PCSCLITE_MAX_MESSAGE_SIZE)
 			{