CWE-126 (缓冲区上溢读取) — Vulnerability Class 417

int processMessageFromSocket(int socket) { int success; char buffer[BUFFER_SIZE]; char message[MESSAGE_SIZE]; // get message from socket and store into buffer //Ignoring possibliity that buffer > BUFFER_SIZE if (getMessage(socket, buffer, BUFFER_SIZE) > 0) { // place contents of the buffer into message structure ExMessage *msg = recastBuffer(buffer); // copy message body into string for processing int index; for (index = 0; index < msg->msgLength; index++) { message[index] = msg->msgBody[index]; } message[index] = '\0'; // process message success = processMessage(message); } return success; }

int main(int argc, char **argv) { char Filename[256]; char Pattern[32]; /* Validate number of parameters and ensure valid content */ ... /* copy filename parameter to variable, may cause off-by-one overflow */ strncpy(Filename, argv[1], sizeof(Filename)); /* copy pattern parameter to variable, may cause off-by-one overflow */ strncpy(Pattern, argv[2], sizeof(Pattern)); printf("Searching file: %s for the pattern: %s\n", Filename, Pattern); Scan_File(Filename, Pattern); }

/* copy filename parameter to variable, no off-by-one overflow */ strncpy(Filename, argv[2], sizeof(Filename)-1); Filename[255]='\0'; /* copy pattern parameter to variable, no off-by-one overflow */ strncpy(Pattern, argv[3], sizeof(Pattern)-1); Pattern[31]='\0';