Changing Your LinkedIn Password Still May Not Have Kept Your Account Safe

This seems like security/session management 101

I kinda hope/expect any password change will invalidate all client side tokens when I am using an app web based or otherwise. At the least, invalidate it when I do something that requires a rights check. ( IE adding scammer@someplace.tld as the recovery email or w/e ).

I'm fairly certain that LinkedIn has little or no regard for user privacy and security. Why do I say this? Even as early as 2007, I noticed that LinkedIn displayed 3 rotating links to people I might be 'interested' in connecting with. And among names of people I knew well, one or two names repeatedly popped up that were vaguely familiar, but they were neither friends nor friends of friends (as far as I knew). Then it dawned on me -- one of those vaguely familiar names is a person living halfway around the world whom I've never met except for the email inquiry he made to a mailing list and his followup to my response. The only way LinkedIn (or any real person) could think that we had any sort of affinity is if they read that singular email thread in my email. Yes, my email+password combo for LinkedIn was my email+password combo for my email.

So LinkedIn was snooping in my email, for which they would needed to have saved my password in plaintext (or equivalent) somewhere.

If I needed further proof, after my changing my email addr that I used to login to LinkedIn, I stopped getting those invasive people suggestions. I then googled (again, back in 2007) about LinkedIn and snooping in people's email accounts, and an interview with the CEO had a brief mention of it, where the CEO flatly denied any sort of privacy breach.

I think we need to supersede the commentary of LinkedIn's incompetent handling of security and privacy (which they spectacularly proved already) with the idea that not only do they not give a flip, but they want to keep it that way for their own maximum benefit.

I don't think they were logging into email surreptitiously without you first doing a "Find My Friends" thing--that's clearly illegal. However, my guess is that they did at least the following (which is still creepy, IMHO):

- Used phone contacts from the mobile app to use as suggestions. I noticed a serious uptake on weird connection suggestions after I first installed the app a few years back. Checking it out on a proxy, I noticed that it wasn't using SSL, either, so I uninstalled that puppy quick. I assume they've fixed this between then and now.

- The "Find My Friends" from the Web and Mobile works both ways - so if someone you've emailed in the past chooses to do this, you start seeing them in your suggestions list. If I remember correctly, their original method for doing this was an actual login to email (which may be what happened to you; I don't know if there's any way to get them to clear out those suggestions once you've done it. I contacted Support about this awhile back & couldn't get an answer). What seemed weird to me about this is that all my wedding vendors popped up at the same time as suggestions...like they all got on LinkedIn at once or something.

- If you look at someone's profile or they look at yours--even anonymously, you're linked somehow for suggestions. I've seen people I haven't talked to or emailed in 15 years and three email accounts ago recommended, as well as their spouses(!). Serious privacy issues here if you spend a few minutes thinking about the possibilities. ;)

A quick tip--would bet many HN folks already know this, but I've talked to bunches of people who don't: Unless you explicitly set the "Select what others see when you view their profile," option (and keep checking it occasionally - just found mine was reset somehow), anyone whose profile you've viewed can see that you've viewed it. I love this feature (from the who's-viewed-me side, at least), but it's still creepy and something to be aware of if you're LinkedIn stalking someone...

Also, it does look like they finally added a "Security" checkbox in Settings to always browse using https - would highly recommend setting that one if you haven't already.

I suspect that it is much worse than that.

The fact that the mobile app can still access LinkedIn means that there is an authentication back door that it uses. What does that back door look like? Clearly it does not care about your password.

If someone studies the mobile app and figures out how it does this authentication trick, then we'll know the damage. Is there a universal authentication where you just need to know the person's name to connect? Is there a table inside of LinkedIn that can simply grant access? (If the blackhats can get a dump of the user table, they probably can manage to insert things into other tables.) Whatever the mechanism turns out to be, it provides a way for the blackhats to bypass security and access your stuff even if they do not know your password. And the odds are depressingly high that they'll be able to do it even if they never knew your password.

Yes, sha2 is more than sufficient for protecting auth tokens. If it's not, the problem is your auth tokens are too simple.