Code in supabase-js calls `getSession()`, which now throws a warning when using in combo with ssr

[j4w8n]

Bug report

• [x] I confirm this is a bug with Supabase, not with my own application.
• [x] I confirm I have searched the Docs, GitHub Discussions, and Discord.

Describe the bug

When using @supabase/supabase-js and @supabase/ssr, a console warning is now thrown whenever you fetch from the DB on the server-side. e.g. await supabase.from('profiles').select('*'). Based on what I'm seeing in supabase-js code, this would throw during other invocations as well - like calling an edge function or storage. This landed with auth-js@2.63.0.

The warning is: "Using supabase.auth.getSession() is potentially insecure as it loads data directly from the storage medium (typically cookies) which may not be authentic. Prefer using supabase.auth.getUser() instead. To suppress this warning call supabase.auth.getUser() before you call supabase.auth.getSession()."

As you'll see from my repro code, I'm not calling getSession() at all. The underlying issue is that supabase-js code calls getSession(), and therefore the warning is outside of a dev's control.

In supabase-js, it's called here, which is invoked here.

Supabase uses getSession() to grab the user's access_token, in order to authenticate fetches. This is understandable, and I suspect this issue is an unintended side effect from the auth-js code.

To Reproduce

https://github.com/j4w8n/getsession-warning

• clone, install, create your .env with supabase url and key, npm run dev, visit localhost on port 5173

Expected behavior

The console warning should not throw when the getSession() call is outside a dev's control.

System information

• Version of ssr: [^0.3.0]
• Version of supabase-js: [^2.42.0]

Additional context

There have been issues created on other repos. https://github.com/supabase/auth-js/issues/873 https://github.com/supabase/auth-helpers/issues/755

[jdgamble555]

To reiterate, we should not be making an extra fetch to verify a session, unless a user is logged in. A non-logged in user should not have to call getUser() at all, as it is an unnecessary fetch that will slow down all apps.

J

[julien-blanchon]

How can we even disable this !

[j4w8n]

To reiterate, we should not be making an extra fetch to verify a session, unless a user is logged in. A non-logged in user should not have to call getUser() at all, as it is an unnecessary fetch that will slow down all apps.

J

https://github.com/supabase/auth-js/pull/876 should at least partially address your concern, once it lands. It won't fire the network request for getUser if there's no logged-in user. It does return an error in that case, so I'm not sure how that might affect apps, depending on if/how people handle an error for that call.

[jdgamble555]

I don't want to

To reiterate, we should not be making an extra fetch to verify a session, unless a user is logged in. A non-logged in user should not have to call getUser() at all, as it is an unnecessary fetch that will slow down all apps. J

supabase/auth-js#876 should at least partially address your concern, once it lands. It won't fire the network request for getUser if there's no logged-in user. It does return an error in that case, so I'm not sure how that might affect apps, depending on if/how people handle an error for that call.

I don't want to call getUser() at all, so that is not really addressing anything. I should be able to call getSession() to see if there is a local session at all, and then all getUser() to verify it or revalidate it if and only if there is a session. So, that is unrelated IMO.

J

[julien-blanchon]

I'm very concerned with this design choose, I don't understand why you did that ...

[j4w8n]

I don't want to

To reiterate, we should not be making an extra fetch to verify a session, unless a user is logged in. A non-logged in user should not have to call getUser() at all, as it is an unnecessary fetch that will slow down all apps. J

supabase/auth-js#876 should at least partially address your concern, once it lands. It won't fire the network request for getUser if there's no logged-in user. It does return an error in that case, so I'm not sure how that might affect apps, depending on if/how people handle an error for that call.

I don't want to call getUser() at all, so that is not really addressing anything. I should be able to call getSession() to see if there is a local session at all, and then all getUser() to verify it or revalidate it if and only if there is a session. So, that is unrelated IMO.

J

I misunderstood then. I'm sorry.

[itsmikesharescode]

Any update?? :3

[Gbuomprisco]

I personally only use it on marketing pages to check if a user is logged in and display their profile avatar/name - and do so to avoid a request that would slow down important pages.

I'd personally either add a way to disable the log, or disable the log in production, or disable them altogether and simply mention this in the docs (which I can now see do so)

[ElectricCodeGuy]

Would it be possible to fix silly issue?? It have been reported one week ago and it seems like Supabase team are on vacation or something?

const originalWarn = console.warn.bind(console.warn); console.warn = (msg, ...params) => { if ( msg.includes('Using supabase.auth.getSession() is potentially insecure') ) { return; } originalWarn(msg, ...params); };

To suppress it

[itsmikesharescode]

any update 🥲 im using SvelteKit

[j4w8n]

any update 🥲 im using SvelteKit

No updates. I'm not sure how visible it is to the team at this point. I'd imagine they've been prepping for the "big announcement" next this week.

[itsmikesharescode]

Hope, this gets fixed sooner. 😭

[kangmingtay]

Hey everyone, apologies for not acting on this sooner - the team decided to add the warning log in getSession with good intention because we noticed that many folks were using it insecurely on the server-side to "verify" that a user is logged in. It was designed to be used safely on the client-side but with the move to react server components, this posed a problem when it's used on the server-side since the user details in the session can be faked by the client.

Our immediate priority was to ensure that no one uses it in an insecure fashion and we might have been over-zealous with logging it as a warning. Since this is security sensitive, we wanted to inform everyone in the quickest and most obvious manner. We have since made the fix https://github.com/supabase/auth-js/pull/879 to cut down on the noise, and only log the warning when the user object is accessed from the session returned in getSession .

We appreciate all of your feedback, and hopefully this makes this easier for you; however, if there are other concerns about this or the fix, please let us know.

[j4w8n]

I can confirm that @supabase/auth-js@2.63.1 resolves this issue. Thanks!

@kangmingtay, I can close this if you'd like, or we can leave it open for however long you want.

[chbert]

@j4w8n I'm using "@supabase/supabase-js": "^2.42.5", which should have @supabase/auth-js@2.63.1 afaik. But I still get the logs.

[j4w8n]

@j4w8n I'm using "@supabase/supabase-js": "^2.42.5", which should have @supabase/auth-js@2.63.1 afaik. But I still get the logs.

That should be the warning about the user object, correct? Not the getSession warning.

[eluchsinger]

I get this warning when calling the supabase.auth.updateUser function.

[j4w8n]

I get this warning when calling the supabase.auth.updateUser function.

Can you clarify the warning? If it's the "Using supabase.auth.getSession()..." warning, you should be able to update supabase-js and that will no longer log. If it's the other warning: "Using the user object...", then I briefly mentioned the updateUser() edge case on an issue I recently created - https://github.com/supabase/auth-js/issues/888

[eluchsinger]

@j4w8n you're right. It's the following error:

Using the user object as returned from supabase.auth.getSession() or from some supabase.auth.onAuthStateChange() events could be insecure! This value comes directly from the storage medium (usually cookies on the server) and many not be authentic. Use supabase.auth.getUser() instead which authenticates the data by contacting the Supabase Auth server.

[chbert]

@j4w8n I'm using "@supabase/supabase-js": "^2.42.5", which should have @supabase/auth-js@2.63.1 afaik. But I still get the logs.

That should be the warning about the user object, correct? Not the getSession warning.

@j4w8n Sorry, for my late reply! Yes, correct: Using the user object as returned from supabase.auth.getSession() or from some supabase.auth.onAuthStateChange() events could be insecure! This value comes directly from the storage medium (usually cookies on the server) and many not be authentic. Use supabase.auth.getUser() instead which authenticates the data by contacting the Supabase Auth server.

[j4w8n]

Thanks @chbert. Then these two issues are going to be more relevant for you: https://github.com/supabase/auth-js/issues/873 https://github.com/supabase/auth-js/issues/888