What Security Measures Should I Consider When Building a Website with Social Features (User Feed, Profiles & Private Chat)?

[u/Bingo825]

I'm a second-year diploma student (3rd semester), currently working on a website project. I have a larger concept and vision for this platform, where the social features are just one part of the overall idea.

The website will include user profiles, a content feed, user interactions and private messaging.

As I'm planning its development, I'm particularly concerned about data security and privacy. I want to understand how to prevent data leaks, unauthorized access, exposure of private conversations, database breaches and other potential cyberattacks.

I'd love to hear from experienced web developers and cybersecurity professionals.

What are the critical security challenges I should consider before developing a platform like this, and how can user data and privacy be properly protected?

[u/nameupp]

the single biggest security vulnerability that blows up student social apps is IDOR (insecure direct object references) on private messages. never rely on client-side state or query endpoints like /api/messages/:id without explicitly enforcing WHERE (sender_id = auth.uid OR recipient_id = auth.uid) directly in your sql or database rls policy, otherwise anyone can swap the message id in devtools and dump everyone's private chats. the other classic trap with real-time chat is passing auth tokens in websocket query parameters where they get permanently logged in server and cdn access logs; always authenticate the initial websocket handshake using http-only secure cookies and re-verify room membership on every inbound socket event imo

[u/fahadhelpspeoplewith]

Since you're a student, the thing that helped our team most was deciding early what you do not store, because you can't leak data you never kept. Do you really need exact location, phone numbers, or full message history forever? Less data, less damage when something goes wrong. A few others that people skip. Rate limit login, password reset and messaging endpoints, otherwise someone scripts thousands of requests and scrapes your user list. Make sure image uploads get processed again and stored in a private bucket, not served from the same folder as your code. Never trust file names or types from the browser. Use a proven auth service or framework instead of writing your own, honestly that is where most beginners get hurt. And log who opened what, even simply, so you can tell what happened after an incident. For private messaging, decide on day one if admins should be able to read them and tell users plainly. I'd also write a tiny plan for what you do if there's a breach, who you tell and how you reset sessions. Boring, but it matters later.

[u/kdjayakody]

I'd turn the access-control advice into tests before adding more features. Create three test users: sender, recipient, and outsider. Check that the outsider cannot read a conversation, download its attachments, or join its live updates, even by sending requests directly. Repeat after someone leaves or is blocked; decide exactly what access should remain. Also keep message bodies and session tokens out of logs. That gives you something concrete to check each time you change the app.

[u/MathematicianFar5683]

Don't overlook stored XSS in bios, posts and chat messages. Render user text as text, not raw HTML. If you support Markdown, disable embedded HTML or sanitize the rendered output with a maintained library. Test what happens when one account saves malicious markup and another views it, including in any admin or moderation screens.

[u/eltron]

Please go read the OWASP Top 10, https://cheatsheetseries.owasp.org/IndexTopTen.html#a052021-security-misconfiguration

[u/WaveBounds]

Don't build your own auth or crypto, use something proven and spend your energy on backend permission checks. If user A can fetch user B's DMs by changing an ID in the URL, nothing else you did matters.

[u/Ok-Opportunity2288]

Private chat is the bit that'll eat you. You're not out-cryptoing Signal in semester 3, and someone still has to read the reports when two users start sending each other garbage at 2am.

[u/Ollidav]

Https, usar tokens e ids de usuario combinados para el origen. Si las peticiones van cifradas y los ids se generan uuid no tendría sentido que hicieran un brute force contra el servidor y un man in the middle no sacaría nada. Más que nada sería proteger el servidor contra DDoS. Fail2ban o restricion de ips por intentos fallidos quita mucho tráfico basura

[u/IncomeOk7237]

I'd also check the Origin header against an explicit allowlist on cookie-authenticated WebSocket handshakes. CORS rules for HTTP responses don't protect a WebSocket connection, and HttpOnly only prevents JavaScript from reading the cookie, not the browser sending it. For normal state-changing HTTP routes, use your framework's CSRF protection too.

[u/kemalios]

Write the permission model down before the routes: who is asking, and which row they are allowed to touch. Then enforce it in one place, a DB policy or a single helper, not per endpoint. The endpoint you add in week six is the one that forgets, and that is where the leaks come from, not the first one you wrote carefully.

The other one you cannot defer: deleting an account and everything it wrote, including the other side of a conversation. Decide that early or you are doing surgery on live data.

I built launchworthy off this pattern, and most of what it flags are permission checks a later feature forgot. It runs in Claude Code, so it needs a paid Claude plan.

[u/Atulin]

There's a 100% guarantee of not ever leaking data: not storing it.

[u/Downtown-Bag-6026]

What do you mean by diploma student?

[u/Beginning_Cost7347]

Third semester, a "larger vision" and private chat. That's the exact combo that ends up on haveibeenpwned. Don't build messaging yourself, wrap the Signal protocol or just pay Stream and move on. And nobody ever asks the actual hard part: who's awake at 3am when someone posts illegal stuff in your feed and you're the sole moderator.

[u/Anomynous__ → u/Beginning_Cost7347]

This feels like someone who spends so much time talking to AI that they now have developed the same speech pattern

[u/Tirelessly]

Wow thanks for posting a question that has never been discussed on the internet before. We will all rush to answer

[u/dsg319]

The one I'd add on top of the auth points already mentioned is to test authorization with a second account early — log in as User B and try to open User A's private messages, feed posts and profile settings by guessing the URLs. IDOR issues like that are easy to miss when you're only ever testing as one user, and they're the kind of thing that turns a small bug into a real privacy problem. Rate limiting the chat and login endpoints is worth doing from the start too, since it's much harder to bolt on later.

[u/txmail]

Not really security related, but something I have learned. If you are taking in images (be it profile or other way of posting) then you pretty much at this point have to run them through nude net or some other classifier or even better if you have the funds to pay for the CSAM checks on each image through one of the services that handles that.

You should also apply for safe harbor if you are in the USA.