The writeup archive

The evidence fields, in the required order, are:

The site is a hash-routed SPA (nothing renders from the server). The useful surface is all in the JavaScript:

The employee directory exposed internal employee records without enforcing that the requested record belonged to the logged-in user. The leaked debug_reference for another employee led…

The recovered evidence passes the AES-GCM authentication check supplied in the challenge.

server.py is a blind Schnorr signing service over secp256k1. On connect it sends its public key for that connection:

The input to enter into the app's "whisper" field is:

The supplied mosaic_0417.png is a 256 × 300 indexed-color PNG. It contains a palette, two text chunks, nine IDAT chunks, and no data after IEND. The picture looks like colorful noise.

The challenge page identifies the target as the legacy problem search. The Problems page shows that searches are sent to:

Attack chain:** Jinja2 SSTI (RCE as webapp) → forged TPM attestation against the internal vault (VAULT-114) → leaked tpm-admin SSH key → TOCTOU symlink race in the measure-and-run sudo…

The capture is plain, unencrypted MQTT from a dozen smart-home devices. Two devices hide data in covert channels:

The capture is plain, unencrypted MQTT from 12 smart-home devices. Two devices hide data in covert channels:

A small industrial controller exposes a line-oriented ASCII maintenance service over TCP. Factory service mode is supposed to be reachable only by on-site technicians with a dedicated…

This flag was confirmed accepted by the challenge submission system.

The attachment is an Android diagnostic app for the LumoWise LW-7 smart bulb. Its UI accepts a 16-byte challenge response as 32 hexadecimal characters. The actual validation and flag…

The box protects its flags with a warden (/opt/warden/warden.py, runs as root). The real flag files live in /var/lib/warden/real/, while the decoys live in /var/lib/warden/decoy/. The…

ECHO-9's watchdog recovery preserved its boot counter and restarted its transmit sequence. This caused a reset event to reuse the AES-CTR nonce of an earlier service response. The…

Unzipping the archive gives a second zip with four logs. Three of them (auth.log, network.log, system.log) each have a flag-looking string, but they're all decoys.

redacted/XploitX_Stego03_Participants/extractions/NIGHTINGALE_memo_RESTRICTED.docx.extracted/0/word/document.xml 1. Zero-width chars in the RE: line → key. Map \u200b=10, \u200c=00,…

Incident Case File: #2026-2184-GAMMA | PORT 0xBEEF (HYPER-NESTED) Category: Networking / Network Forensics / Cryptography Target Flag Format: XploitX[beta]{...} (decoded as XploitXβ{...})

Binary protocol: u32 command | args, reply u32 status | u64 value (cmd 5 replies with two qwords: arena base + code pointer).

The challenge is a chain of nested archives ("nested stream package").

The MIDI file is a container. A ZIP is appended after the MIDI tracks, and inside it is a PNG whose top three pixel rows hide the flag as a 1-bit-per-pixel bitmap. The other files are…

file on double_exposure.jpg reveals a JPEG comment:

We are given a set of ECDSA-style signatures over the secp256k1 curve whose nonces were generated with a bias: the top 8 bits of each nonce are zero, i.e. every nonce k satisfies