A growing collection of CTF writeups from competitions around the world.
Each writeup walks through the thought process and solution step by step.

---

Competitions

OliCyber

OIC — Web Security

#	Challenge	Technique	Writeup
01	NoRobotsHere	robots.txt enumeration	EN · IT
02	Headache	HTTP response headers	EN · IT
03	JustAReminder	Client-side authentication	EN · IT
04	SitoVuoto	Source code inspection	EN · IT
05	ClickMe	Client-side variable manipulation	EN · IT
06	CookieMonsterArmy	Session cookie forgery	EN · IT
07	RickRoller	HTTP redirect interception	EN · IT
08	ATooSmallReminder	Session ID enumeration	EN · IT
09	iForgot	Git repository exposure	EN · IT
10	ConfuseMe	PHP type juggling	EN · IT
11	PasswordChanger3000	IDOR / Token forgery	EN · IT
12	BasicSQLi	SQL injection	EN · IT
13	IGotMagic!	File upload RCE	EN · IT
14	LightOrDark	Local File Inclusion	EN · IT
15	FlagsShop	Client-side price tampering	EN · IT
16	TimeIsKey	Timing attack	EN · IT
17	ZioFrank	Admin account takeover	EN · IT
18	CStyleLogin	PHP strcmp type juggling	EN · IT
19	MakeAWish	preg_match array bypass	EN · IT
20	CuriousGeorge	—	EN · IT
21	Sn4ckSh3nan1gans	SQL injection (Base64 JSON)	EN · IT
22	ShellsRevenge	File upload RCE	EN · IT
23	Admin's Secret	SQL injection / Auth bypass	EN · IT
24	TrulyRandomSignature	Predictable RNG seed	EN · IT
25	TIMP	Command injection via cowsay	EN · IT
26	IfYouHaveNoTimeJustDon'tWait	SQL injection (blacklist bypass)	EN · IT
27	ShellsRevenge2	File upload + LFI (RCE)	EN · IT

OIC — Network Security

#	Challenge	Technique	Writeup
01	Useless	PCAP metadata / capinfos	EN · IT
02	SniffnByte	Hex-encoded TCP payload	EN · IT
03	ProtocolloDatagrammaUtente	UDP stream reassembly	EN · IT
04	G4tto	HTTP object export (JPEG)	EN · IT
05	EasyStream	HTTP object export (HTML)	EN · IT
06	PocaCola's Recipe	HTTP multipart + AES ZIP	EN · IT
07	Wordwang	Input pattern discovery, automation	EN · IT
08	SicurezzaDeiTrasporti	TLS 1.3 decryption (SSLKEYLOG)	EN · IT
09	That's A Lot Of F's	Covert channel in MAC/EtherType	EN · IT
10	CHAOS	TCP chaos, timestamp sorting	EN · IT
11	AMelodyInMyHead	Weak nonce, replay attack	EN · IT
12	SuperSecretAgent0x42	XOR challenge-response, key extraction	EN · IT
13	YouCompleteMe	Side-channel (response size, ECB leaks)	EN · IT
14	DNSE-MailSecurity	DNS SPF CNAME enumeration	EN · IT
15	QuantumTransportLayer	TLS SNI/ALPN, SAN analysis	EN · IT

OIC — Misc

#	Challenge	Technique	Writeup
01	Bright Sun	Visual steganography (highlights)	EN · IT
03	Dashed	Multi-layer encoding (Morse → hex/binary → Base64 → ROT13)	EN · IT

ITSCyberGame

ITASEC 2025

Category	Challenge	Technique / Note	Writeup
Misc	Decode	Hidden QR in image	EN · IT
Misc	The Legend of the Hidden Code	Metadata (Exif)	EN · IT
Misc	Misty Morning	Bit plane (Blue channel)	EN · IT
Crypto	Mystery Code	ROT13 substitution	EN · IT
Misc	Dreams Within Dreams	Strings in image file	EN · IT
Crypto	Grand Valse	T9 predictive text cipher	EN · IT
Web	There Is No Spoon	Acrostic in HTML comment	EN · IT
Crypto	The Signal	Binary Morse, Base64, ROT47	EN · IT
Misc	The 1337 Vault	Nested 7z extraction	EN · IT
Misc	Corrupted Memories	Corrupted PNG header fix	EN · IT
Crypto	The Answer to the Ultimate Question of File	Single-byte XOR (key=42)	EN · IT
Web	Stairway to Flag	Client-side source inspection	EN · IT

Girone 2026

1a_Giornata

Category	Challenge	Technique / Note	Writeup
Misc	Fischietto	PNG stego + WAV (Morse)	EN · IT
OSINT	SubWaySurfer	Google-indexed comments; Base64 then ROT13	EN · IT
Web	BZZZZZ!	API chaining; session cookies & header manipulation	EN · IT
SSH	Bosh	Bash alias misdirection; bypass with absolute paths; hidden dotfiles	EN · IT
SSH	FollowTheRainbow	PROMPT_COMMAND inspection; investigate non-standard binaries (/usr/local/bin/color-changer)	EN · IT
OSINT	Deep Dive	SQLite forensics; hex + Base64 decoding	EN · IT
Web	IlPiccoloNegozioOnline	Base64 cookie tampering / client-side cookie manipulation	EN · IT
Misc	Ma che bello era il 2013...	Zip password cracking (rockyou); hex decode	EN · IT
Software	OrbitalDecay	UTF-16LE in .rodata	EN · IT
Software	WhoAreYou	Buffer overflow + null byte injection	EN · IT
Network	NetworkSpy	Writeup coming soon	EN · IT

2a_Giornata

Category	Challenge	Technique / Note	Writeup
Crypto	TheGroceryLeak	Repeated-key XOR; key hidden in ODS prices	EN · IT
Misc	Six76Seven	Audio stego / LSB or appended data	EN · IT
Misc	IlBackupSbagliato	Encrypted backup / hardcoded creds	EN · IT
Pwn	CorruptedCode	Noisy text parsing; regex + automation	EN · IT
SSH	GhostInTheLogs	Logs exposure; base64 in syslog	EN · IT
SSH	HawkinsLab	Upside-down SSH key; unicode fix	EN · IT
Web	PlayStation.Store	Client-side promo + cookie tampering	EN · IT
Software	TheSecretShop	PCAP for creds; hidden dev endpoint	EN · IT
Software	WhoAreYou2	Ret2win with null byte trick	EN · IT
Software	FerrisWheel	Cyclic additive cipher (Rust)	EN · IT

3a_Giornata

Category	Challenge	Technique / Note	Writeup
Web	Your money are safe (Bank)	SQL injection + IDOR	EN · IT
Web	Enterprise Access Gateway v2.1	alg=none token forgery	EN · IT
Crypto	Fish	Many-Time Pad (XOR reuse) + weak password	EN · IT
Network	But it was cheap!	PCAP analysis; ONVIF / Base64 exfiltration	EN · IT
Software	BackupUnlocker	Static binary analysis; runtime string encoder + Vigenère-like transform	EN · IT
Software	EmojiCipher	—	EN · IT
Misc	Emergency Access	Restricted shell; hidden DEBUG command and trivial arithmetic unlock	EN · IT

In presenza 2026 PADOVA

Quarti di Finale

Category	Challenge	Technique / Note	Writeup
OSINT	Girolamo Trombetta	Satellite imagery geolocation → local extinction	EN · IT
Misc	The Insider Threat	Forensic DB analysis (SQLite)	EN · IT
Web	Workflow Runner	Insecure Python pickle deserialization → RCE	EN · IT
Software	Labyrinth Protocol	Custom verification reverse → chunk enumeration	EN · IT
Network	We Are Under Attack!	PCAP analysis; blind boolean-based SQLi extraction	EN · IT
SSH	Internal Service	SSH key crack → internal HTTP access	EN · IT
Crypto	Shuffled Snapshot	Textbook RSA per-block (no padding) + block shuffle	EN · IT

Semifinale

Category	Challenge	Technique / Note	Writeup
Web	HOLD IT!	Score oracle → greedy brute, stored XSS to steal admin cookie, path traversal via encoded slashes	EN · IT
Crypto	Is that a...?	False extension (magic bytes), PNG chunk metadata, AES-ZIP appended after IEND, LSB stego	EN · IT
Misc	Broken	Hidden .git/ + HEAD renamed; QR degraded by single-pixel flips	EN · IT
Misc	The Data Exfiltration	Accidental API key commit → mass exfiltration; correlate git/logs/S3/billing	EN · IT
Misc	Matrix	Obfuscated client-side JS; hardcoded arrays reveal flag	EN · IT

Finale

Category	Challenge	Technique / Note	Writeup

FCSC

FCSC 2022 — Misc

#	Challenge	Technique / Note	Writeup
01	A l'envers	Automation / string reversal	EN · IT
02	QRCode	QR repair — restore finder pattern centers	EN · IT
03	Wi‑Fi	WPA2 decryption / Wireshark (pcapng)	EN · IT

FCSC 2022 — Web

#	Challenge	Technique / Note	Writeup
01	Header	HTTP header auth via custom header	EN · IT

FCSC 2022 — Crypto

#	Challenge	Technique / Note	Writeup
01	A l'aise	Vigenère (known key)	EN · IT

---

Repository Structure

<Competition>/
└── <Edition or Year>/
    └── <Category>/
        └── <Challenge>/
            ├── writeup-en.md
            └── writeup-it.md

Each challenge folder contains writeups in English and Italian.

---

License

This repository is for educational purposes only. All challenges belong to their respective organizers.