Krebsonsecurity.com has an expired SSL certificate

https://krebsonsecurity.com/

by k_sze • 6 years ago

74 63 6 years ago

krebsonsecurity.com

dildozer2• 6 years ago

It is a different Krebs, but still ironic

dboreham2• 6 years ago

Other way around no, the Krebs in the news is the different Krebs?

dildozer2• 6 years ago

Yes Chris Krebs was fired, Brian Krebs is krebsonsecurity, no relation

dboreham2• 6 years ago

Assume this is deliberate, since real domain hijackers would use a valid cert. Also helps to ensure browser vendors don't disable cert validity bypass. Very clever.

lozaning• 6 years ago

Based on his tweet it sure seems like he forgot to renew, and this isn't some kind of genius move to keep anyone honest.

https://twitter.com/briankrebs/status/1328863446105010177

panarky• 6 years ago

That tweet says "Despite what the browsers may be saying, the site is still safe to visit."

Is it though?

Asking people to ignore browser warnings seems like bad advice from a security expert.

tvbuzz• 6 years ago

Fake news designed to cut down on DDOS

ludditetech• 6 years ago

Chuckle, happens to the best of us - obviously.

k_sze2• 6 years ago

I'm surprised that Brian Krebs still uses Comodo.

Why not LetsEncrypt with automated renewal?

mpd3• 6 years ago

While you're not paying for the cert, there is certainly still a cost involved.

mehrdadn7• 6 years ago

I never understood why browsers don't just go ahead and load websites with expired certificates and merely provide milder warnings for a few weeks/months. The expiration date doesn't mark any meaningful real-world event that indicates the private key might be compromised... it's just an expiration date. Why set off all the alarms and make the user freak out and make it so hard to visit the site as soon as the certificate becomes 1 millisecond too old? It seems to violate common sense.

whoisjohnkid• 6 years ago

That would open a new vector of attack where an attacker would simply have to compromise any of your previous certs; not necessarily an easy feat but still a new vector

mehrdadn7• 6 years ago

No it doesn't? All that happens is the previous cert would be accepted with a milder warning for a few weeks (not permanently) after you get a new one.

It's just a small grace window to let users still be able to use the site. Just like an expiration date on your milk. There's no need to toss it out immediately just because an extra nanosecond passed.

stefan_• 6 years ago

In a world where you can simply compromise a cert of your choice we can get rid of the TLS theatre altogether.

No, the world we have is one where these expiry mishaps happen all the time, and everyone would be better served if certs had a warning expiration date in addition to the red alert one. It's the old "don't delete a customer the second they are late on a single payment" thing that everyone long recognizes as good practice.

paxys• 6 years ago

Why should every browser pick a random expiration date to enforce when there is already one agreed upon by everyone and embedded in the certificate?

im3w1l3• 6 years ago

Everyone is on lets encrypt nowadays, which means they had no say in they expiration date. They merely said yes to "take it or leave it".

t0astbread• 6 years ago

There might be an official standardized explanation for this but the way I see it, certificate expiry has two reasons:

1) It's an assurance that the verification of identities/servers (or whatever) behind the certificate is at least somewhat recent

2) Certificates imply a loose agreement between the certificate holder and the world that the certificate holder keeps the private key safe. The expiry date automatically ends that agreement.

Time is relevant in both cases but it's not that relevant that the timing is exact in web browsing. Identity verification is still about as fresh one day after expiry. The second case is a bit more critical but chances are certificate holders don't leak their private keys immediately after expiry.

Giving a "grace period" with noticeable but non-blocking warnings (something like the "this site recently had an account breach" popup in Firefox perhaps) might cause website operators to find out about the problem without disrupting the service. It would be a good idea to standardize the length of the grace period.

Off the top of my head I can only think of one situation that might turn problematic and that is when an expired certificate gets compromised. I'm not familiar with how CAs do it but I hope renewal automatically revokes the renewed certificate already. It would also need to be possible to explicitly revoke an expired certificate if something like a grace period existed.

bawolff8• 6 years ago

I think it makes more sense to give warnings in the 72 hours prior to expiration, rather than after. At least browser console warnings.

Or have two expires in a cert - soft and hard.

bisby• 6 years ago

That's just... moving the expiration date. Why not provide those milder warnings BEFORE the current expiration date?

If there's just an arbitrary point in time where after which we start warning people and then another point where the cert expires... Why move "expiration" around.

mehrdadn7• 6 years ago

That's just... moving the expiration date.

No it's not, you still get a (slightly) nagging warning. Just one that's much milder (without the red alert, fear-mongering, etc.) and still lets people use the site for a while.

Why not provide those milder warnings BEFORE the current expiration date?

I indeed almost suggested this, but the problem is the site owner hasn't done anything wrong in that case, so the warning would be an actual false alarm.

Klathmon• 6 years ago

I feel like it would be better to show a warning earlier rather than after it expires.

Browsers could start showing warnings that a cert is expiring soon when something like 5% of the cert lifetime is left (with a max of like 1 month for some of those crazy long lifetime certs).

mehrdadn7• 6 years ago

I feel like it would be better to show a warning earlier rather than after it expires.

The problem is this is an actual false alarm in that case; nothing has actually gone wrong. Nobody likes to get a warning about something that's still good before its expiration.

mobilio• 6 years ago

Certificates have a great timespan like "do not use before" and "do not use after".

So you can't simply shown outdated certs because this make time totally useless. But you also can't shown cert from the future.

Other sad news - new browsers set that certs can have lifetime only for year and month: https://www.michalspacek.com/maximum-https-certificate-lifet... to effective fight against certs that are too long lifetime.

So this make a window for installing new cert exactly 42 days. And many people will fail on this trap soon.

webnanners• 6 years ago

This happened to braintree/paypal like a month ago.. and broke their API

jcims• 6 years ago

Happens to all sorts of folks - https://venturebeat.com/2015/04/04/gmails-ssl-certificate-fo...

x87678r• 6 years ago

Like many I've been burnt by this problem. I have a rule now where no certificate should ever be within 6 months of expiry, ideally we should renew every month.

prepend2• 6 years ago

I hate getting in arguments with a few sysadmins and certificate salespeople how long certificate periods are perfectly safe.

I’d rather have 5 year certs and rely more on revocation than have this stupid exercise where people must renew every year or 13 months that just so happens to collect tons of rent seeking income from a few firms.

It’s kind of like how the shift to non-expiring passwords. We were trying to correct for the risk of a compromised password by making it harder to have secure passwords. I think we’re better off with having really strong passwords that only ever get changed when necessary and allowing this my monitoring login actions for weird stuff.

NobodyNada• 6 years ago

people must renew every year or 13 months that just so happens to collect tons of rent seeking income from a few firms

Isn’t it primarily free CAs like LE that are pushing for shorter expiration times?

IIRC the primary argument is not about security or safety, but rather that shorter certificate lifetimes encourage companies to automate certificate renewal/make it a regular part of their business routine. If you only have to renew a certificate every five years, then it’s really easy to forget.

prepend2• 6 years ago

I think it’s just as easy to automate a monthly renewal as a five year renewal.

The argument that gets presented to me is that shorter times reduce the risk of someone compromising the cert and pretending to be the real server. But that risk requires a pretty motivated attacker to also compromise DNS or server farm and that probably doesn’t matter because they will plan around any renewal cycle.

bawolff8• 6 years ago

The password comparison doesn't really fit. We stopped requiring it because users behaved badly when forced and caused a net reduction in security.

Sysadmins dont pick their private key. They dont write the private key on a post it. None of the reasons for not doing password expiry apply here.

Primary benefit of shorter certificates is it probably makes it easier to punish CAs that dont follow the rules.

SAI_Peregrinus• 6 years ago

Revocation doesn't really work well. Attackers only have to DOS the connection to the revocation list, and then they can use the revoked certificate freely. The revocation checks fail often enough that browsers don't even show a warning when this happens.

spullara• 6 years ago

Why don't systems that use certificates have a configurable webhook they call to warn of such things?

jijji• 6 years ago

echo "certbot-auto renew --nginx" > /etc/cron.weekly/renew_certs.sh

szc• 6 years ago

I personally think that TLS certificate expiry should be a server problem not a client problem.

The TLS server code is the piece that is using the certificate every time a page is requested.

Why doesn't server code log an error warning that the certificate is going to expire?

Why doesn't the server just stop serving connections when the cert has expired?

Stopping connections ought to get the attention of the service owner rather than force clients to use out-of-band mechanisms to reach the service owner.

Alternatively perhaps imminent expiry should be a trigger for renewal or some other alerting mechanism.

Is there a callback like this in current TLS API stacks that could be used to make this work? (I'm not super familiar with TLS server side APIs, I know there are client callbacks for certificate validation).

It would probably be wise to do the check carefully so as to not consume too many resources. A well thought out mechanism could trigger an external process for notification or even automatic renewal - even when needing to cross a privilege boundary, perhaps touching a file or an IPC message.

I think this would be slightly better than some of the current setups for things like Let's Encrypt that end up running many times unnecessarily. Would be a much better fit for resource constrained embedded devices.

[edited: added back a sentence I inadvertently removed]

Krebsonsecurity.com has an expired SSL certificate

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