static int bson_validate_string( bson *b, const unsigned char *string,
                                 const int length, const char check_utf8, const char check_dot,
                                 const char check_dollar ) {

    int position = 0;
    int sequence_length = 1;

    if( check_dollar && string[0] == '$' ) {
        if( !bson_string_is_db_ref( string, length ) )
            b->err |= BSON_FIELD_INIT_DOLLAR;
    }

    while ( position < length ) {
        if ( check_dot && *( string + position ) == '.' ) {
            b->err |= BSON_FIELD_HAS_DOT;
        }

        if ( check_utf8 ) {
            sequence_length = trailingBytesForUTF8[*( string + position )] + 1;
            if ( ( position + sequence_length ) > length ) {
                b->err |= BSON_NOT_UTF8;
                return BSON_ERROR;
            }
            if ( !isLegalUTF8( string + position, sequence_length ) ) {
                b->err |= BSON_NOT_UTF8;
                return BSON_ERROR;
            }
        }
        position += sequence_length;
    }

    return BSON_OK;
}
The software performs a calculation that can produce an integer overflow or wraparound, when the logic assumes that the resulting value will always be larger than the original value. This can introduce other weaknesses when the calculation is used for resource management or execution control.