Yet another Hacker News

223 points ahlCVA 2 hours ago 58 comments

tecleandor 2 hours ago | parent

This is gonna be great to sniff apps in a couple older Android phones I have around. Hope they're not pinning certificates.

selcuka 38 minutes ago | parent

Can't you install your own CA to Android phones?

j027 16 minutes ago | parent

You can, but since android 7 IIRC apps don’t trust the user store by default (unless you have root and add it to the system store or patch the app to trust the user store)

DrammBA 2 hours ago | parent

I love how someone's security disaster becomes someone else's feature.

xp84 2 hours ago | parent

I agree. We may as well make some lemonade out of these lemons. IMHO the ability of companies to 'securely' close off hardware and software from their users is a sad casualty of the success of cryptography, and not a feature.

r3trohack3r 1 hour ago | parent

Most things have tradeoffs

At some point you’re forced to stack rank two or more of your values in a case where they’re mutually exclusive

tonymet 2 hours ago | parent

I seriously laughed at the flag. public wifi is going to be lit.

MajorTakeaway 1 hour ago | parent

What about using a VPN on public wifi?

thway15269037 33 minutes ago | parent

At places where I did work anything private over even properly protected wifi was forbidden after several wifi vulns in 2018. So the only thing available on company's wifi was vpn gateway and page with manual how to set it up.

So, not trusting anything wireless is a thing for almost a decade.

Bratmon 1 hour ago | parent

As the percentage of technology controlled by people actively using it to do evil increases, so does the net value to society of a trivially-expliotable zero-day.

shrubble 2 hours ago | parent

If I’m understanding correctly, you could sniff the communication between your Smart TV and the manufacturer using this method?

quotemstr 1 hour ago | parent

If the TV isn't older than a few years, if it's not checking CRLs, and if it hasn't yet patched itself.

kevin_nisbet 1 hour ago | parent

Possibly. But some manufacturers may not have the full set of roots, use a private authority, or do certificate pinning.

the_snooze 1 hour ago | parent

As long as the smart TV still trusts eMudhra, then yeah. You'll want to super careful and prevent the TV from pulling updates that could revoke that trust.

skeledrew 2 hours ago | parent

This is how fame happens.

maxlin 50 minutes ago | parent

infamy*

xp84 24 minutes ago | parent

They deserve every bit of it. Their name will be a synonym for sloppy security. "Oh shit, you got Emudhra'd"

seniorsassycat 2 hours ago | parent

How much of a boon is this for jailbreaking, reverse engineering, and mitm really?

bryancoxwell 1 hour ago | parent

Been wondering this as well. I also don’t really understand the mitm to jailbreak pipeline

flexagoon 1 hour ago | parent

Some smart devices pull config files from a server. By mitming that, you can change the config to enable some sort of developer mode on the device.

qwertyforce 1 hour ago | parent

Maybe intercept firmware update and then reverse engineer it and find rce?

mrheosuper 34 minutes ago | parent

The fw could be encrypted

ruined 18 minutes ago | parent

military grade SSL

himata4113 1 hour ago | parent

client on startup asks: hey server do you have any ads for me

server: here are latest ads

btw, the ads are capable of code execution for whatever reason so now you have an RCE on your hands for your client

sippingabonedry 1 hour ago | parent

Wonderful.

Anyone else bother to notice iOS still trusts 2 of the forged certs on the test site? I'd like to politely know what the fuck is going on because this is far from being "fixed".

xuki 1 hour ago | parent

Which iOS version? 27.0.1 here and they're all revoked for me.

snailmailman 1 hour ago | parent

FWIW i havent updated my ios, I'm on 26.6.2, and they all got revoked for me. The revocation shouldn't require an iOS update.

TYPE_FASTER 53 minutes ago | parent

I’m on the same version, and according to https://emudhra.we-have-a-problem.com/ they have not been revoked for me. Maybe phased rollout.

sippingabonedry 1 hour ago | parent

26.7.1 still (randomly) trusts 2 out of the 12 compromised chains. All browsers impacted.

Edit: I'm not the only one with this issue:

https://www.reddit.com/r/iphone/comments/1xbvxgd/emudhra_cer...

My best guess is it's soft-failing on a failed OCSP lookup?

robrain 38 minutes ago | parent

Mine were all blocked this morning when I informed my family of the mitigation methods.

I've just been rechecking everything and both iOS and MacOS browsers (Safari and Orion tested) now accept one (for MacOS, 27.0.1) or three (for iOS, 27.0.1) of them. I know the revocation is not an OS update, just including the version number for completeness.

EDIT: iPadOS with the same browsers continues to pass the tests.

Further EDIT: iPadOS now accepts one of them. This has to be a load issue on the "got a problem site", surely? Maybe a check for a certificate error message that never hits because a timeout beats it?

sippingabonedry 6 minutes ago | parent

> Further EDIT: iPadOS now accepts one of them. This has to be a load issue on the "got a problem site", surely?

No, because it lets you successfully navigate to the forged CA test site.

Try clicking the link containing the CA's name for any that fail the test.

kccqzy 8 minutes ago | parent

Apple’s OCSP server may be overloaded?

I don’t know if possible on iOS but I remember multiple incidents where people recommended turning off CRL and OCSP on macOS to speed things up. That even used to be a setting in the GUI. https://i0.wp.com/i.imgur.com/XVHWCNz.png

wildmXranat 1 hour ago | parent

Someone should've coined this disaster as "QuattroFail" to give it a little panache and international mystery

gnabgib 1 hour ago | parent

"4" was only some of the keys (they were all <256).. ByteFail seems more accurate

bombcar 34 minutes ago | parent

OneByteWonder

mintflow 1 hour ago | parent

Haha, this is quite interesting to test if you need to update various of program (if they do not use the sys ca chain)

xmcp123 1 hour ago | parent

Never thought there would be a silver lining on this issue. Fuck yeah.

Confiks 1 hour ago | parent

It's almost a shame it includes the private key and doesn't bruteforce it in-band for every request.

subscribed 1 hour ago | parent

OMG, that would be brutal

brirec 6 minutes ago | parent

Would it? The private key is 4.

https://tech-insider.org/emudhra-ca-private-keys-compromised...

wilkystyle 2 minutes ago | parent

I took the parent's comment to mean "brutal" as in an absolute burn/roast.

taneq 2 minutes ago | parent

Guaranteed random, chosen by fair roll of a die.

(Credit to the relevant xkcd. :D )

judge2020 31 minutes ago | parent

I would've at least appreciated once per session

0xbadcafebee 1 hour ago | parent

Remember twenty years ago when tools like this were "controversial" because you could "just download it and hack anyone" ? Except the only systems you could hack were... insecure ones... so people updated their systems to resist the tools' attacks, and we all ended up more secure.

deadbabe 1 hour ago | parent

Can someone explain the significance here, a lot has happened in 24 hours.

Gigachad 1 hour ago | parent

An Indian Certificate Authority was found to have a private key that’s literally the number 4. So using that you can sign valid https certs for anything that isn’t checking the revoked list.

brendoelfrendo 1 hour ago | parent

They had 8 intermediate certs with private keys under 1 byte (<256). The most egregious was 4, but any of those 8 were pitiful.

bombcar 33 minutes ago | parent

It would’ve almost been better if the eight keys were just 1 2 3 4 5 6 7 8

jolmg 1 hour ago | parent

https://en.wikipedia.org/wiki/EMudhra#2026_intermediate_cert...

> On October 17, 2026, browser root programs received a report that the private keys of eight eMudhra intermediate certificates had been compromised. The private keys were 4, 56, 66, 115, 155, 156, 230, and 237. A P-384 elliptic-curve private key normally has about 384 bits of entropy, but these keys had between 3 and 8 bits.

lambda 1 hour ago | parent

Oh, nice. I was thinking of setting up a proxy for this for testing, nice to just have it working out of the box.

CGamesPlay 58 minutes ago | parent

This looks like it's using the emSign root path, which is useful, but the AAA root path is equally useful in different cases. The AAA root path was disabled for https on root stores newer than February 2025, but has been in root stores since forever. Meanwhile the emSign root path was only included in root stores since ~2018 and got removed in October 2026.

So from the perspective of hacking old IoT devices, if your device hasn't been updated since 2018, the AAA path should work; if since February 2025, either path works; if since October 2026, the emSign path.

codys 29 minutes ago | parent

There is an MR to add the AAA root path open to allow picking either one.

mhils 9 minutes ago | parent

I didn't expect this commit to end up on HN, otherwise I would have done the full integration in one go. :) https://github.com/mitmproxy/mitmproxy/pull/8503 adds the AAA root path.

cherioo 51 minutes ago | parent

I thought this cert only recently gets trusted, so only newish but not too new devices would be vulnerable. Am i misunderstanding how this works?

SAI_Peregrinus 34 minutes ago | parent

The flaw is egregious enough that the root cert which signed them (emSign ECC Root CA – G3) is getting removed from trust stores. We know 8 ridiculously weak keys got made, but we don't know that 0 slightly less weak but still unacceptable keys got made. What if they issued a CA key with 80 bits of entropy? That's enough that brute force would take more time than it's been since the disclosure, but not so long that they'd be considered at all secure (they should have 384 bits of entropy). So everything that root signed is untrustworthy, possibly everything the CA has signed. The G3 root is from 2018 IIRC, so lots of potentially exposed devices.

chatmasta 40 minutes ago | parent

Looking forward to setting this up manually after my agent refuses to do it. Like the good ol’ days.

seaal 34 minutes ago | parent

Just ask one of the Chinese models.

closetheloopdev 38 minutes ago | parent

I created a proxy using the 6 compromised eMudhra CA keys (2 of the 8 are code-signing and not for TLS). I initially tried just one (the one with d=4) like in the commit, but it did not seem to work for anything. Once I added all 6 keys, I was able to intercept some.

I was mainly interested in testing which IoT devices are affected and protecting them, not trying to sniff their traffic since it's been a long day. My proxy thus just intercepted and forwarded the traffic upstream using a fresh TLS connection that does not use the compromised keys.