Roo CTF 2025

hosted by University of Missouri-Kansas City, in person only placed 1st overall, beating out high school, university, and open; ts was peak

Roo CTF 2025: Include (tuxops) title: “include” date: “2025-10-25” author: “TechnoDot (technodot)” description: “imported” TechnoDot, mrnullone Given the URL https://include.cyberroos.org, find the flag. Navigating to the URL, we are greeted with a simple page that switches themes. We see that the theme is conveyed by a get parameter in the URL, between the themes light and dark. Opening up DevTools, we see that the X-Powered-By header is PHP/8.0.30, shining a light onto how we proceed. Attempting to set a non-existent theme (such as ?theme=flag) results in no styling at all. Examining the page source, we see that the style has a PHP error in it. ...

Roo CTF 2025: Paddington (tuxops) title: “Paddington” date: “2025-10-25” author: “TechnoDot (technodot)” description: "" mrnullone, TechnoDot Given the capture file chall.pcap, find the flag. chall.pcap was modified to hide the flag. Opening the file, we see that almost every packet is the Modbus protocol. Putting not modbus into the filter bar yields a few TCP packets, which seem unimportant. Looking through the packets, we notice that in the ascii contents section, there are some jumbled ascii characters as well. There seems to be no rhyme nor reason to these characters, and it can reasonably be inferred that we’ll have to do deeper digging. There’s also a lot of malformed packets, but I can’t seem to make anything of them. Sorting through packets, one value that seems to change consistently is the Register Value. ...

Roo CTF 2025: Split-Screen (tuxops) title: “split-screen” date: “2025-10-25” author: “TechnoDot (technodot)” description: "" TechnoDot (https://github.com/TechDudie) Provided with the split-screen executable, find the flag. REQUIREMENTS: Ghidra, WSL (for Windows); we don’t talk about Mac Try running the executable. On Windows, run it in WSL. ┏━(Message from Kali developers) ┃ ┃ This is a minimal installation of Kali Linux, you likely ┃ want to install supplementary tools. Learn how: ┃ ⇒ https://www.kali.org/docs/troubleshooting/common-minimum-setup/ ┃ ┗━(Run: “touch ~/.hushlogin” to hide this message) (base) ┌──(technodot㉿VIVOBOOK)-[~] └─$ cd /mnt/c/Users/technodot/Downloads/ (base) ┌──(technodot㉿VIVOBOOK)-[/mnt/c/Users/technodot/Downloads] └─$ chmod +x ./split-screen (base) ┌──(technodot㉿VIVOBOOK)-[/mnt/c/Users/technodot/Downloads] └─$ ./split-screen [timeline] expectation and reality drift apart. press enter to sync> you keep rewinding but nothing changes. try again later. (base) ┌──(technodot㉿VIVOBOOK)-[/mnt/c/Users/technodot/Downloads] └─$ Loading the executable into the dogbolt decompiler, we can see different decompilations to varying detail. Hex-Rays offers the clearest code, with all of the print statements verbatim in the code. ...