    readString: (dest, maxLen) => {
      if (typeof dest === 'number') {
        maxLen = dest;
        dest = undefined;
      }

      const len = self.readUInt32BE();
      if (len === undefined)
        return;

      if ((buffer.length - pos) < len
          || (typeof maxLen === 'number' && len > maxLen)) {
        return;
      }

      if (dest) {
        if (Buffer.isBuffer(dest))
          return bufferCopy(buffer, dest, pos, pos += len);
        return buffer.utf8Slice(pos, pos += len);
      }
      return bufferSlice(buffer, pos, pos += len);
    },
The software constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.