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Severe Unauthenticated RCE Flaw (CVSS 9.9) in GNU/Linux Systems Awaiting Full Disclosure

Posted by suprjami@reddit | linux | View on Reddit | 95 comments

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95 Comments

Good-Entrance-2967@reddit

If only Linux was rewritten in Rust. Majority of these CVEs (including potentially many others that just aren't disclosed yet) wouldn't even exist
View on Reddit #36817113

Kurgan_IT@reddit

No one knows anything about this, I really HOPE it's in something not critical like ipv6, so I can just disable it and go on, otherwise I's so fucked...
View on Reddit #36409400

Jertzukka@reddit

Not IPv6, the author said so.
View on Reddit #36424390

Kurgan_IT@reddit

This makes me feel like I have to cry
View on Reddit #36428671

wademealing@reddit

I'll save you some tears, assuming the stated vendors did agree to the score. The C:L I:H A:L Confidentiality, so they can log in as 'some user' aka, not root. Integrity: so they can modify anything as that user. Availbility: they can probably shut down whatever daemon / vector they abuse, but whatever it is it isnt kernel. So its likely some kind of daemon, its probably something like multicast DNS or some desktop application listening on a socket. This isnt even the worst thing ive seen this week.
View on Reddit #36437914

Kurgan_IT@reddit

If it's just some daemon, I can disable it and survive for the time needed to fix it. Even ssh, no problem, just disable it from outside temporarily or limit it. I am VERY afraid of something like TCP stack because then we are TRULY screwed.
View on Reddit #36440877

gtrash81@reddit

Well, unless it is some basic daemon, like dhcpd or bind9 or stuff like that.
View on Reddit #36445041

wademealing@reddit

Just replying for your sleep. It's cups. Rhel doesn't even ship it as affected by default.  I wonder if other distros do.
View on Reddit #36581510

wademealing@reddit

It has the wrong score to be a protocol level CVE, unless this guy scores the rating wrong. I wouldnt' loose sleep over this.
View on Reddit #36441141

primalbluewolf@reddit

> I really HOPE it's in something not critical like ipv6, Speak for yourself!
View on Reddit #36517468

AryabhataHexa@reddit

From original poster I saw it as critical rated.
View on Reddit #36478003

AryabhataHexa@reddit

https://youtu.be/8PbTZaWFzf8
View on Reddit #36478112

mrvanez@reddit

This is soooo funny is such a wrong way! :)
View on Reddit #36424544

TheSleepyMachine@reddit

There isn't much code present in systems for 20 years. It is either extremely common lib, or critical stuff like ssh or network handling Sooooooooo....
View on Reddit #36418803

DeeBoFour20@reddit

Well that's vague as hell. I feel like they could at least disclose what project has the vulnerability. Is it the kernel? SSH? glibc?
View on Reddit #36425487

eclipseofthebutt@reddit

I read a rumor that it's to do with CUPS.
View on Reddit #36430631

undersquire@reddit

But then it wouldn't affect "all GNU/Linux systems" like the article claims, since not every GNU/Linux system is using CUPS. It would still be a big deal however, and I would think that a CUPS vulnerability would affect macOS and BSDs too right?
View on Reddit #36434515

FormerSlacker@reddit

since not every GNU/Linux system is using CUPS. I'm pretty sure every major distro has CUPS installed out of the box? Look at all the vendors tagged in the CVE, even Apple is there and they use CUPS https://pbs.twimg.com/media/GX7YsBqXEAACZa2?format=jpg&name=medium
View on Reddit #36441476

CubicleHermit@reddit

> I'm pretty sure every major distro has CUPS installed out of the box? Plenty of server-focused distributions don't; CUPS is a dependency (or transitive dependency) of all the major desktop environments, but if you're installing a system that doesn't need a full desktop environment (only headless X, or no GUI at all) unless you're intentionally doing a print server why would you want CUPS?
View on Reddit #36482952

FormerSlacker@reddit

I’m Im not sure what exactly you’re replying to? I said it ships with every major disto out of the box not every distro permutation that exists. Even on servers it’s often installed by default because print servers as you mentioned. It’s probably one of the most widely installed daemons across all nix variants. BTW it was just disclosed that it is in fact CUPS
View on Reddit #36538446

CubicleHermit@reddit

"Every major distro" is not the same as "every major DESKTOP distro." RHEL, Ubuntu Server and Debian's base system profile are all major distributions. If you install RHEL and don't tell it to install a desktop environment or install Ubuntu server, I'm pretty sure neither one will have CUPS installed, although pulling in pretty much any desktop environment in your kickstart will pull it in. I don't have time to pull a base image to check, but running CUPS on an external-facing system is close to malpractice, and having any ports open from CUPS to the open internet is crazytown.
View on Reddit #36553393

FormerSlacker@reddit

> "Every major distro" is not the same as "every major DESKTOP distro." My brother in christ when I say every major distro on a subreddit where 99% of the content is desktop user centric what exactly did you think I mean? People were speculating it was Cups because of its wide install base across nix*s, (some servers too), turned out it was Cups and here you are being insanely pedantic for some reason
View on Reddit #36556113

CubicleHermit@reddit

I was clarifying my shorter original point, because it didn't seem you got it. And there are also a lot of us here who run Linux as part of our jobs, and that isn't typically on a desktop environment. There are a lot more servers out there in on the internet (both physical and even more so virtual) than desktop Linux users, and more embedded Linux systems than either. Some of those do run CUPS, although very few of them should.
View on Reddit #36568941

vertigoacid@reddit

I would argue it's even worse than that. I'd be willing to bet desktop linux usage isn't even 1% of the total linux hosts in the world - the market share for desktop vs server are basically a mirror. >95% of web servers are linux, <5% of desktops are linux Coupled with plenty of default cupsd configs even when you do install it only binding to localhost rather than 0.0.0.0, and this is a big yawn as far as the breadth of the impact IMO.
View on Reddit #36555291

undersquire@reddit

Mainly just desktop systems. I doubt many servers or IoT devices would have CUPS installed and running. Iirc, Debian also does not pre-install CUPS out of the box, although I'm not sure if it does if you chose to install the desktop variant in the installer. FreeBSD doesn't pre-install CUPS. However it definitely could be CUPS given how widely used it is, but I also would think that the vulnerability would not be nearly as devastating since I doubt many people expose CUPS servers publicly to the internet. As someone else mentioned earlier, I also thought it could be something in GNU coreutils or glibc, since the articles all specifically claim "GNU/Linux". Although, given that the vulnerability is claimed to be RCE, I would think it needs to be something specifically with networking or the kernel itself.
View on Reddit #36465349

pppjurac@reddit

I have cupsd on my nuc server (debian) because it acts as basic print server for home and has single inkjet attached. But it is local network only, not open toward internet and behind fw.
View on Reddit #36529627

vertigoacid@reddit

Neither does RHEL or derivatives. Even Ubuntu doesn't install CUPS out of the box on a server (it might on a desktop, don't have one handy to look at). If it's in GNU coreutils or glibc, then you're not going to have impact on the BSDs or MacOS (they each implement their own libc, CUPS fits. But the number of systems listening on 631 on a public IP, with a custom CUPS configuration to allow unauthenticated traffic from somewhere besides localhost? Well, those are already owned hosts. ASCII art penises are flying out of the attached printer until it's out of paper or ink.
View on Reddit #36480178

BeatTheBet@reddit

Could you be so kind to link the source of the image? I know you said "vendors tagged in the CVE", but the linked thread says there's no CVE assigned yet, no? (P.S: Excuse my ignorance, I see it comes from X/twitter but I've never used that platform so I know if I can somehow back-track from the image link)
View on Reddit #36449233

FormerSlacker@reddit

The dude who reported the bug posted that image in the twitter thread: https://x.com/evilsocket/status/1838222308919365678
View on Reddit #36449482

NatoBoram@reddit

> You’re unable to view this Post because this account owner limits who can view their Posts.
View on Reddit #36466238

BeatTheBet@reddit

I get > Hmm...this page doesn’t exist. Try searching for something else. But I'll take your word for it that it was posted by "@evilsocket" on X. Thank you.
View on Reddit #36450144

FormerSlacker@reddit

Elon made it so that you have to be signed into twitter to see replies to tweets
View on Reddit #36450608

Phoenix591@reddit

nah the guy who reported the vulnerability put his account in "protected mode" where only followers ( and he has to approve who gets to follow him) can see his posts.
View on Reddit #36453944

pitust@reddit

It's a CVSS 8.8 in CUPS. No idea where they got the 9.9 from, it requires user interaction (the user has to print to a malicious printer) and the printer needs to be on the same network (for DNS-SD autodiscovery to autodiscover the malicious printer).
View on Reddit #36535194

undersquire@reddit

Yeah I just heard it was in CUPS. This will not be nearly as big of a deal then that some people are making it out to be.
View on Reddit #36561185

jmcunx@reddit

> I would think that a CUPS vulnerability would affect macOS and BSDs too right? *BSD default to use lpd, not cups. Cups is only installed if you pull in a package that depends upon it (like firefox). I believe most people on *BSD stick with lpd(8) instead of using cups. If only Linux people knew how to write portable code, then things like cups/ dbus ... would not end up on BSD.
View on Reddit #36521190

deja_geek@reddit

The author claims all GNU/Linux systems (plus others). So it could also affect BSD and MacOS. CUPS is a common culprit among all three of those "systems", but also SSH
View on Reddit #36478825

michelbarnich@reddit

I mean to affect literally all systems, it would have to be the Kernel, somewhere in the networking stack.
View on Reddit #36435637

xatrekak@reddit

Systemd has a wide enough install base I wouldn't take an issue with an article claiming it effected all linux systems even if it weren't strictly technically true. Also glibc, openssh and a few other near universal core systems and libraries.
View on Reddit #36440755

penguin359@reddit

OpenSSH runs on macOS, BSD, Windows, and others. This seems to be Linux-specific. glibc is not 100% Linux-specific, but close enough that it's an option besides the kernel.
View on Reddit #36463028

xatrekak@reddit

You can have interactions between components that introduce a vulnerability on one OS and not another like in OpenSSH RegreSSHion. This only impacted systems using glibc despite being an OpenSSH specific vulnerability.
View on Reddit #36463502

FormerSlacker@reddit

> since not every GNU/Linux system is using CUPS. I'm pretty sure every major distro has CUPS installed out of the box?
View on Reddit #36441161

matt_eskes@reddit

Not a rumor. He released early. Confirmed as CUPS
View on Reddit #36567672

EastSignificance9744@reddit

you are him
View on Reddit #36551250

matt_eskes@reddit

CUPS
View on Reddit #36567654

boolshevik@reddit

Such things are supposed to be vague before a patch is published, no? If more info were known then it would narrow down the surface attack for malicious actors to focus, investigate and potentialy find the RCE and exploit it.
View on Reddit #36431533

Far-9947@reddit

This is my guess.
View on Reddit #36484764

djasonpenney@reddit

I understand the dilemma of responsible reporting. This article is annoying as hell because the developers are still working on the mitigation, so no details are available. Sigh.
View on Reddit #36477156

matt_eskes@reddit

This is 6.6 to 7 tops. It’s bad but not THAT bad
View on Reddit #36567609

suprjami@reddit (OP)

It certainly turned out to be over-hyped.
View on Reddit #36567718

matt_eskes@reddit

Yeah I normally don’t get alarmed by CVEs, but this one actually did it to me until I actually saw what it was
View on Reddit #36567771

jerone2@reddit

[https://www.redhat.com/en/blog/red-hat-response-openprinting-cups-vulnerabilities](https://www.redhat.com/en/blog/red-hat-response-openprinting-cups-vulnerabilities)
View on Reddit #36540802

aenae@reddit

> YES: I LOVE hyping the sh1t out of this stuff because apparently sensationalism is the only language that forces these people to fix. Read: They are hyping it to create buzz (it works) so the vendor actually fixes it. It is probably a bug in CUPS (seeing as Apple (creator of CUPS) was the first vendor on his list and *bsd is affected as well). One line in their (now private) twitter also said that the developers failed to see the big impact, as the computer has to be exposed to the internet. (which they countered with 'terabytes of scans showing a lot of computers with that software exposed to the internet').
View on Reddit #36434640

dynamiteSkunkApe@reddit

>Apple (creator of CUPS) This is not factually accurate
View on Reddit #36469827

aenae@reddit

Bad choice of words, i meant they currently maintain the cups project.
View on Reddit #36494217

MetaTrombonist@reddit

FWIW, this is also not true. Apple no longer meaningfully contributes to cups. They only do bug fixes. https://www.phoronix.com/news/Apple-No-More-CUPS
View on Reddit #36539883

AnticitizenPrime@reddit

> was the first vendor on his list The list is alphabetical.
View on Reddit #36516402

SMF67@reddit

CUPS is used for print servers on corporate networks. So while it's not exposed to the public internet, it's still exposed to hundreds of devices that could take advantage of the vuln if even one of them is evil.
View on Reddit #36487689

cyberburrito@reddit

"seeing as Apple (creator of CUPS)" Yes. Apple. Creater of all things. The earth, oxygen, life itself on this planet. CUPS was around long before Apple "created" it.
View on Reddit #36454987

hackingdreams@reddit

> CUPS was around long before Apple "created" it. The guy who wrote CUPS (Sweet) went to work for Apple about three years after he made it, and worked there for nearly two decades on CUPS and printing in general. They even outright purchased the copyright for CUPS from Sweet in 2007 so they could make a BSD/proprietary version they use in their print server now rather than using the GPL'd code, during the first big wave of "no GPL" at Apple. It's not nearly as outlandish as you claim it to be.
View on Reddit #36462758

finite_turtles@reddit

Defence in depth is a thing. Any org that takes security seriously should not have this exposed to the internet. But they would still be scrambling to see if it is exposed internally as well.
View on Reddit #36458839

kuroimakina@reddit

Oh good. Love to see this. I am very much feeling the sentiment listed in the article of “since no details have been released, people are on edge because they don’t have any idea of anything proactive they can do” Like, if there’s a service I can disable for a few days that fixes the problem, I’d really love to know. Guess I’ll just have to wait with all the other “outsiders” (people involved in the CVE process)
View on Reddit #36421575

ilep@reddit

Remove CUPS, the printer daemon.
View on Reddit #36539249

broknbottle@reddit

[https://github.com/OpenPrinting/cups-browsed/issues/36](https://github.com/OpenPrinting/cups-browsed/issues/36) [https://gist.github.com/stong/c8847ef27910ae344a7b5408d9840ee1](https://gist.github.com/stong/c8847ef27910ae344a7b5408d9840ee1) [https://www.evilsocket.net/2024/09/26/Attacking-UNIX-systems-via-CUPS-Part-I/](https://www.evilsocket.net/2024/09/26/Attacking-UNIX-systems-via-CUPS-Part-I/)
View on Reddit #36539209

bobbie434343@reddit

Hope it will have a cool evocative and scary name, a web site and a press-kit.
View on Reddit #36496810

FishHikeMountainBike@reddit

DeepInMyCUPS
View on Reddit #36538072

forthelurkin@reddit

Until then, we should all just resume hand-wringing and crying wolf. The sky is falling, after all.
View on Reddit #36504412

bobbie434343@reddit

Absolutely, and this is also the end of Open Source as well.
View on Reddit #36505521

NonStandardUser@reddit

2024 going wild with CVE streaks
View on Reddit #36407787

suprjami@reddit (OP)

https://threadreaderapp.com/thread/1838169889330135132.html
View on Reddit #36409989

NonStandardUser@reddit

Thanks, the twitter link didn't work for me
View on Reddit #36410051

suprjami@reddit (OP)

I refuse to visit actual Twitter :)
View on Reddit #36412272

Grim-Sleeper@reddit

They renamed from Twitter, to Xitter. It's pronounced like pinyin; think of "X" making the "sh" sound.
View on Reddit #36534954

MatchingTurret@reddit

>I refuse to visit actual Twitter :) But you visit Reddit... ¯⁠\\\\⁠\_⁠(⁠ツ⁠)⁠\_⁠/⁠¯
View on Reddit #36412816

the_abortionat0r@reddit

> But you visit Reddit... ¯⁠\_⁠(⁠ツ⁠)⁠_⁠/⁠¯ Um, do you think the two sites are owned by the same company?...
View on Reddit #36455734

MatchingTurret@reddit

No, of course not. But they are both social media, so I don't see much of a difference.
View on Reddit #36455939

SealProgrammer@reddit

The communities are very different. As one example, Twitter is mostly right-wing people while Reddit is the opposite, etc.
View on Reddit #36480973

themusicalduck@reddit

Twitter is far worse than Reddit. Absolute cess pool.
View on Reddit #36474851

Standard-Potential-6@reddit

Everyone knows only the social media app they use is the decent one. The others are filthy hives of misinformation run by crooks. Obligatory fuck spez.
View on Reddit #36465090

NatoBoram@reddit

Tried to look at it and > You’re unable to view this Post because this account owner limits who can view their Posts. Wow, they can go fuck themselves, too!
View on Reddit #36466155

miawgogo@reddit

given the stuff in the thread, they might be getting harassment over it
View on Reddit #36505161

NatoBoram@reddit

Harassment over very important security discoveries?
View on Reddit #36510715

miawgogo@reddit

eeeeh, absolutists have been bad. But also i was unaware of some Domestic Violence stuff he had perpetrated, so he probably locked out of damage control rather than what i suggested
View on Reddit #36534619

DolitehGreat@reddit

Probably why we shouldn't post these on twitter.
View on Reddit #36533000

birds_swim@reddit

Reddit is weird. Not sure why this isn't the most upvoted post on this subreddit.
View on Reddit #36519111

aliendude5300@reddit

Lots of details omitted here. We need more information to take action on this
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suprjami@reddit (OP)

That's the whole point of a security embargo. Details will be made available with the fix. It isn't fixed yet.
View on Reddit #36471913

aliendude5300@reddit

Sure but they should at least call out which component is affected etc
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suprjami@reddit (OP)

They absolutely should not. That would result in malicious parties scrambling to try and find the vulnerability before it's fixed, potentially exploiting many many victim systems.
View on Reddit #36478392

pppjurac@reddit

And those bad players might know that hole exists since long time ago.
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suprjami@reddit (OP)

Then there is nothing to lose by keeping it quiet until the fix is ready.
View on Reddit #36493087

the_abortionat0r@reddit

God so much speculation and fanfic. Just wait for the release.
View on Reddit #36456015

pppjurac@reddit

but but but there needs to be drama! wait out for response until that expose only as much of system as it is absolutely needed
View on Reddit #36491373

dynamiteSkunkApe@reddit

I'm just over here waiting for the erotic fanfic
View on Reddit #36469736

sylvester_0@reddit

So I'm guessing whatever it is will be patched before the disclosure and people are going to be watching everything like a hawk over the next few weeks.
View on Reddit #36430171