devsoc-unsw · matthew-lim-matthew-lim · May 21, 2025 · Jun 8, 2004
@@ -0,0 +1,50 @@
+# Circles CTF Challenge Write-up (2025 CSESoc/DevSoc/SecSoc CTF)
+
+This is the writeup for solving the Circles CTF challenge.
+
+The goal is to find two secret pieces of text. Combine them in order (Piece 1 then Piece 2) to form the final flag: `RCR{[Piece1][Piece2]}`.
+For example, if the first piece is `ICouldEatLike` and the second piece is `100McNuggets`, then the final flag is: `RCR{ICouldEatLike100McNuggets}`.
+
+## Part 1: The Writing's on the Wall
+
+The `challenge.html` page describes Part 1 as "The Writing's on the Wall" and gives the following hint:
+> "The first piece of the flag is hiding in plain sight, almost on every page of circles. If you're careful and detail-oriented, you'll find it."
+
+This implies the flag piece is located in a common UI element that appears on most pages of the site, such as the main header or navigation bar.
+
+To find it:
+- Sharp eyes: Use a screen with accurate colours to see where it is.
+- OR Inspect Element: Use Inspect element to find the suspicious element.
+- OR Highlighting: Highlight parts of the page with your mouse. Likely the easiest way.
+
+Definitely a beginner friendly and fun challenge.
+
+
+## Part 2: BOTS0101 - Stop Bots from taking our jobs
+
+The `challenge.html` page describes Part 2 as "BOTS0101 - Stop Bots from taking our jobs" and gives the hint:
+> "Today's tech landscape is a freaky one, with a lot of automation going around. Websites often have a guide for web crawlers (like Googlebot) telling them which areas to avoid. But you're not a web crawler, you're a human (surely right), and you can totally avoid it for us."
+
+Some dablling and research tells them to look at the `robots.txt` file.
+
+
+In your browser, navigate to the `robots.txt` file for Circles (`circles.devsoc.app/robots.txt`).
+
+
+The content of `robots.txt` will look something like this:
+```
+User-agent: *
+Disallow: /s3cr3t_p4g3.html
+```
+The line `Disallow: /s3cr3t_p4g3.html` indicates a hidden page that web crawlers are instructed not to access.
+
+
+Go to the disallowed path in your browser (e.g., `circles.devsoc.app/s3cr3t_p4g3.html`).
+
+This page (`s3cr3t_p4g3.html`) will display the second piece of the flag
+
+## Part 3: Combining the Flags
+
+Combine the flags...
+
+Congratulations! You have successfully completed the CTF challenge. 
@@ -0,0 +1,71 @@
+<!DOCTYPE html>
+<html lang="en">
+
+<head>
+    <meta charset="UTF-P">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Circles CTF challenge</title>
+    <style>
+        body {
+            font-family: Arial, sans-serif;
+            margin: 20px;
+            background-color: #f4f4f4;
+            color: #333;
+        }
+
+        .container {
+            background-color: #fff;
+            padding: 20px;
+            border-radius: 8px;
+            box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
+        }
+
+        .hidden-text-container {
+            background-color: #800080;
+            /* Purple background */
+            padding: 10px;
+            border-radius: 4px;
+            margin-top: 15px;
+        }
+
+        .hidden-text {
+            color: #800080;
+            /* Purple text, same as background */
+            font-weight: bold;
+        }
+
+        .hint {
+            margin-top: 20px;
+            padding: 10px;
+            background-color: #e9e9e9;
+            border-left: 3px solid #888;
+        }
+
+        h1,
+        h2 {
+            color: #555;
+        }
+    </style>
+</head>
+
+<body>
+    <div class="container">
+        <h1>Welcome to the Circles CTF challenge for the 2025 CSESoc/DevSoc/SecSoc CTF!!!</h1>
+        <p>Your mission is to find two secret pieces of text. Combine them in order (Piece 1 then Piece 2) to form the
+            final flag: <code>RCR{[Piece1][Piece2]}</code>.</p>
+
+        <p>For example, if the first piece is <code>ICouldEatLike</code> the second piece is <code>100McNuggets</code>
+            then the final flag is: <code>RCR{ICouldEatLike100McNuggets}</code>.</p>
+
+        <h2>Part 1: The Writing's on the Wall</h2>
+        <p>The first piece of the flag is hiding in plain sight, almost on every page of circles. If you're careful and
+            detail-oriented, you'll find it.</p>
+
+        <h2>Part 2: BOTS0101 - Stop Bots from taking our jobs</h2>
+        <p>Today's tech landscape is a freaky one, with a lot of automation going around. Websites often have a guide
+            for web crawlers (like Googlebot) telling them which areas to avoid. But you're not a web crawler, you're a
+            human (surely), and you can totally avoid it for us.</p>
+    </div>
+</body>
+
+</html>
@@ -1,3 +1,6 @@
 # https://www.robotstxt.org/robotstxt.html
 User-agent: *
-Disallow:
+Disallow: /s3cr3t_p4g3.html
+
+# Allow everything else
+Allow: /
@@ -0,0 +1,62 @@
+<!DOCTYPE html>
+<html lang="en">
+
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Secret Found!</title>
+    <style>
+        body {
+            font-family: Arial, sans-serif;
+            margin: 20px;
+            background-color: #f0f0f0;
+            color: #333;
+            text-align: center;
+        }
+
+        .container {
+            background-color: #fff;
+            padding: 30px;
+            border-radius: 8px;
+            box-shadow: 0 0 15px rgba(0, 0, 0, 0.1);
+            display: inline-block;
+        }
+
+        h1 {
+            color: #4CAF50;
+        }
+
+        p {
+            font-size: 1.2em;
+        }
+
+        .flag-piece {
+            font-weight: bold;
+            color: #d9534f;
+            font-family: 'Courier New', Courier, monospace;
+            background-color: #f9f2f4;
+            padding: 5px 10px;
+            border-radius: 4px;
+            border: 1px dashed #d9534f;
+        }
+
+        .instructions {
+            margin-top: 20px;
+            font-style: italic;
+        }
+    </style>
+</head>
+
+<body>
+    <div class="container">
+        <h1>Congratulations!</h1>
+        <p>You've found the second piece of the flag!</p>
+        <p>Flag Piece 2: <span class="flag-piece">And_H3r3_1s_P4rt_Tw0</span></p>
+        <p class="instructions">Combine the first piece (from the challenge page) with this one to form the full flag.
+            Remember the format: <code>RCR{[Piece1][Piece2]}</code>.</p>
+        <p>Get keen for all the epic Circles features coming soon!</p>
+        <p>And good luck with the rest of the CTF!!! - Circles 2025</p>
+    </div>
+</body>
+
+</html>
@@ -82,6 +82,19 @@ const Header = () => {
       <Drawer onClose={() => setShowDrawer(false)} open={showDrawer}>
         <DrawerContent onCloseDrawer={() => setShowDrawer(false)} />
       </Drawer>
+      <span
+        style={{
+          color: '#722ED1',
+          fontSize: '20px',
+          opacity: 0.05,
+          position: 'absolute',
+          left: '20%',
+          top: '1px',
+          zIndex: 2
+        }}
+      >
+        Th1s_1s_P4rt_0n3_
+      </span>
     </S.HeaderWrapper>
   );
 };