char get_header_code(struct hdr_field *hf)
{
   switch(hf->type){
      case HDR_CALLID_T:
	 return 'i';
      case HDR_CONTACT_T:
	 return 'm';
      case HDR_CONTENTLENGTH_T:
	 return 'l';
      case HDR_CONTENTTYPE_T:
	 return 'c';
      case HDR_FROM_T:
	 return 'f';
      case HDR_SUBJECT_T:
	 return 's';
      case HDR_SUPPORTED_T:
	 return 'k';
      case HDR_TO_T:
	 return 't';
      case HDR_VIA_T:
	 return 'v';
      case HDR_ROUTE_T:
	 return 'r';
      case HDR_RECORDROUTE_T:
	 return 'R';
      case HDR_ALLOW_T:
	 return 'a';
      case HDR_ACCEPT_T:
	 return 'A';
      case HDR_CSEQ_T:
	 return 'S';
      case HDR_REFER_TO_T:
	 return 'o';
      case HDR_RPID_T:
	 return 'p';
      case HDR_EXPIRES_T:
	 return 'P';
      case HDR_AUTHORIZATION_T:
	 return 'H';
      case HDR_PROXYAUTH_T:
	 return 'z';
      default:
	 return 'x';
   }
   return 'x';
}

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.