refactor old-9

pwncollege · Sep 1, 2024 · b42cdff · b42cdff
1 parent 8ab1fa0
commit b42cdff
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Showing 6 changed files with 95 additions and 3 deletions.
diff --git a/web-security/level-9/.config b/web-security/level-9/.config
diff --git a/web-security/level-9/DESCRIPTION.md b/web-security/level-9/DESCRIPTION.md
@@ -0,0 +1,5 @@
+Like with SQL injection and command injection, sometimes your XSS occurs in the middle of some non-optimal context.
+In SQL, you have dealt with injecting into the middle of quotes.
+In XSS, you often inject into, for example, a textarea, as in this challenge.
+Normally, text in a textarea is just, well, text that'll show up in a textbox on the page.
+Can you bust of this context and `alert("PWNED")`?
diff --git a/web-security/level-9/run b/web-security/level-9/run
diff --git a/web-security/level-9/server b/web-security/level-9/server
@@ -0,0 +1,22 @@
+#!/opt/pwn.college/python
+
+import flask
+import os
+
+app = flask.Flask(__name__)
+
+@app.route("/", methods=["GET"])
+def challenge_get():
+    return f"""
+        <html><body>
+        <h1>pwnmsg ephemeral message service</h1>
+        The message:
+        <form>
+            <textarea name=msg>{flask.request.args.get("msg", "Type your message here!")}</textarea>
+            <input type=submit value="Make URL!">
+        </form>
+        </body></html>
+    """
+
+app.secret_key = os.urandom(8)
+app.run("challenge.localhost", 8080 if os.geteuid() else 80)
diff --git a/web-security/level-9/victim b/web-security/level-9/victim
@@ -0,0 +1,68 @@
+#!/opt/pwn.college/python
+
+import contextlib
+import urllib
+import sys
+import os
+
+from selenium import webdriver
+from selenium.webdriver.firefox.options import Options as FirefoxOptions
+from selenium.webdriver.firefox.service import Service as FirefoxService
+from selenium.webdriver.common.by import By   
+from selenium.webdriver.support.wait import WebDriverWait
+from selenium.webdriver.support import expected_conditions as EC
+from selenium.common.exceptions import TimeoutException, WebDriverException
+
+os.environ["PATH"] = "/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
+
+@contextlib.contextmanager
+def run_browser():
+    options = FirefoxOptions()
+    options.add_argument("--headless")
+
+    # workaround for ubuntu
+    if os.path.exists("/snap/bin/geckodriver"):
+        service = FirefoxService(executable_path="/snap/bin/geckodriver", log_path="/dev/null")
+    else:
+        service = FirefoxService(log_path="/dev/null")
+    driver = webdriver.Firefox(service=service, options=options)
+
+    try:
+        yield driver
+    finally:
+        driver.quit()
+
+if len(sys.argv) <= 1:
+    print(f"Usage: {sys.argv[0]} URL")
+    sys.exit(1)
+
+url = sys.argv[1]
+url_arg_parsed = urllib.parse.urlparse(url)
+try:
+    assert url_arg_parsed.hostname == "challenge.localhost", "hostname should be 'challenge.localhost'"
+    assert url_arg_parsed.port in {None, 80, 8080}, "port should be 80 or 8080"
+except AssertionError as e:
+    print(f"Invalid URL: {e}")
+    sys.exit(2)
+
+print("Visiting the URL!")
+with run_browser() as browser:
+    try:
+        browser.get(url)
+        print("URL loaded...")
+        WebDriverWait(browser, 1).until(EC.alert_is_present())
+    except TimeoutException:
+        print("Failure: JavaScript alert did not trigger...")
+        sys.exit(3)
+    except WebDriverException as e:
+        if "can%E2%80%99t%20establish%20a%20connection" in str(e):
+            print("Connection error! Is the service running?")
+        else:
+            print(f"Failure: {e}...")
+        sys.exit(4)
+    else:
+        if url_arg_parsed.port is None or url_arg_parsed.port == 80:
+            print("Alert triggered! Your flag:")
+            print(open("/flag").read())
+        else:
+            print("Alert triggered! Now do it on the real service (port 80)!")
diff --git a/web-security/module.yml b/web-security/module.yml
@@ -38,7 +38,6 @@ challenges:
   name: XSS 3
 - id: level-9
   name: XSS 4
-  description: Exploit a cross site scripting vulnerability with more complicated context
 - id: level-10
   name: XSS 5
   description: Exploit a cross site scripting vulnerability to cause a user action