GhostLock, a stack-UAF that has existed in all Linux distributions for 15 years
nebusec.ai
UAF = Use After Free (https://en.wikipedia.org/wiki/Dangling_pointer)
nebusec.ai
Two boot looped, I had to enter recovery and the other just powered off [0].
The demo modifies the wallpaper on supported Pixel devices.
[0] IonStack https://rootme.nebusec.ai
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Tip: Install a Chromium flavor browser (Chromite) separate from the main browser.
Disable Javascript and hardware accelerated video decoder (commonly exploited) from the flags page and enable reader mode to fix broken JS-dependent websites when browsing blogs and random sites on your personal devices, else dedicate a tablet.
It doesn't have a web browser or, virtually, anything of use... but I think it supports enough of a web browser to log in into wifi captive portals.
This would almost surely work there too, though.
The exploit/POC (call it what you want) ran or appeared to have executed because:
1. I saw output on the Firefox tab when I navigated to <https://rootme.nebusec.io/b9e3f1a4-7c82-4d6e-9a51-2f8c4b3e0d...>.
2. I saw some output from the execution of the POC.
However, after I went to <https://rootme.nebusec.io/b9e3f1a4-7c82-4d6e-9a51-2f8c4b3e0d...> the phone froze and refused to respond to any input. The only thing that worked was restarting, which I wonder how it works given the, I think, the kernel has hung. Does anyone know how the kernel is able to respond to events whilst the system has hung? The screen remains on with the partial output of the execution of the POC until the screen saver kicks in ...
It would be nice to get a `Dockerfile` to build the exploit/POC.
I take it you did NOT unlock the bootloader?
> Two boot looped, I had to enter recovery and the other just powered off [0].
Absolutely crazy that it is possible to brick someone's phone via an exploit but ... hey.
After the power off what happened? Do things seem normal?
When it entered recovery mode where you able to get the phone in a clean state again? I take it that you did?
I'd really like to run this but I, ideally, do not want to run something random from the internet. It's a shame there is no `Dockerfile` to build this exploit/POC. All I want is LPE to `root` on a Samsung (Snapdragon) phone.
Honor 10 - Moto G04 - Poco X3
Poco is unlocked.
There is no brick on any, they're boot loader bugs and unrelated to the exploit. Recovery "reboot" was used.
You need to modify it to root, the example only crashes the kernel.
It takes a few seconds, and redirects to about:blank
Android 13, last update 3 years ago, firefox 140
Maybe prevented by the JShelter extension?
https://addons.mozilla.org/en-US/firefox/addon/javascript-re...
And we don't usually worry about them, because an application with normal user privileges can already to so much damage.
But this exploit can be triggered from inside a tightly sandboxed process, such as firefox's isolated browser process. Which means the attacker now only needs to chain two exploits together: One javascript exploit to get local code execution in an isolated sandbox, and this one to jump all the rest of the way to kernel mode.
Which means, you should update both firefox, and your linux kernel.
Thank you for emphasizing this important detail.
> you should update both firefox, and your linux kernel
No doubt, update all the things! My point was, it can most likely wait until Monday.
That's not meant to be snide, just true, I think.
Many (maybe most) containers actually default to running programs as root. Kernel exploit not required.
The "root" you get in docker is not actually root outside of the namespace the container in running in.
Assuming no bugs in the kernel, it should not be able to do anything more than the UID that it's mapped from.
(Privileges are still limited by seccomp filters blocking some syscalls, and there's SELinux to block some other stuff, but it's still the actual root user without user namespaces, I think?)
Confinement still leverages dropping some root caps, seccomp, various other namespaces, etc.
People still should use user namespaces (and tools like Podman and Incus do by default) but basic stuff like that is not the reason.
https://stackoverflow.com/questions/33013539/docker-loading-...
Not sure about running rootful though. I don't really use rootful containers personally.
While there is a feature to do with UID mapping, it doesn't actually work/isn't usable/nobody uses it in current docker iirc.
Therefore root in the container very much is root on the host.
My mistake, leaving out some adjective one could interpret as a misunderstanding of containers as an effective (etc.) security boundary. Fool me 100+ times and all that.
There must be at least a triple-digit number of CVEs by now demonstratimg that in practice containers are a thinner layer of security (perhaps not quite as thin as the classic recommendation of running SSH on a nonstandard port, but that might be leaning toward the safer side of analogies vs. malicious code!) rather than a boundary like virtualization (not perfect but a best practice for isolation).
Nothing is a security boundary anymore.
I would have hoped that only a few of us are so misinformed as to do that.
from ssh to node, so much stuff showing every other week. might as well call everything remote unless you run 100% behind wireguard or something.
I'm all ears now
It requires being able to execute arbitrary code on the machine in userspace. If you have that, most of the time you don't even care about kernel level exploits.
https://nebusec.ai/research/v8-maglev-incorrect-phis-untaggi...
This is the browser part.
Please tell me you are trolling me and not this stupid.
Backporting an old kernel should be possible, but the only indicator is the system update changelog that explicitly mentions it, I rarely see CVEs mentioned in changelogs on any smartphone. A tool to test the vulnerability is the only way.
Any compromised app on the Play store or external can get root access instantly, but we can still rely on trust and audits when installing apps which should always be the rule.
I suspect that this will be added to all Google Play integrity levels, limiting many apps from being installed on unpatched phones in the future.
That's not the case with browsers with random sites and ads which is hardly avoidable, having any sandbox escape is now more severe considering that it bypasses the app container. It's similar to JailbreakMe on iOS [0]
How the cluster f*k of the Android update situation Google has allowed this to happen really needs a regulator to step in.
Planned obsolescence is supposed to be illegal in Europe.
The alternative would be for the hardware market to be less consolidated (the government keeps allowing Qualcomm to buy up competitors) so that the chip companies would have to compete on things like this. But that's no excuse for Google to be sitting on their hands when they could fix it too.
Just like Microsoft with Windows.
You do realize that a full kernel vulnerability like this allows you to feed falsified information to SafetyNet? Just like DRM, it gives the developer the illusion of control, but doesn't do anything to actually improve "safety" or "integrity".
It's silly that whenever I see a vulnerability like this, all I can think about is "finally, a way to get control over my own devices back". Once again, Stallman was right.
https://www.gnu.org/philosophy/right-to-read.en.html
Personally, I'll use this to root my Android TV and Chromecast devices and remove the shitty ads in the launcher (which Google added after I bought the devices!).
Good news for reusing old phones and taking control.
*as in replace
The proper solution is one we had with desktop computing for decades. If you keep the key material on your eID or bank card, you don't need a locked down operating system. Which then allows devices to live for much longer.
We're slowly losing the war on General Purpose Computing.
https://media.ccc.de/v/28c3-4848-en-the_coming_war_on_genera...
So you want a bank card/ID card to be required each time you use Google Pay? What's the point of Google Pay then.
Maybe I could even duct-tape it to my phone if I really want to do that.
That then allows you to do secure NFC credit card payments even on a rooted phone with custom ROM.
Not a great solution.
Which hasn't been an issue since Chip & PIN became required, 22 years ago (at least over here).
From then your Google Pay account is authorized to initiate charges until you tell your bank otherwise and you don't need the card again unless you want to sign up for Venmo etc.
And it makes things easy if someone steals your phone, because you just sign into the payment processor and deauthorize the device or, if they've already changed your password etc., sign into (or go to) the bank and deauthorize the payment processor.
A lot of phones don't receive any upgrades after 1 or 2 years...
I wish that Google would have forced vendors to implement a proper hardware abstraction (uefi or similar) so that a single kernel could run on any smartphone, just like it's the case for PCs...
https://source.android.com/docs/core/architecture/kernel/gen...
The problem being that there are many millions of people who can't afford to replace a phone they only recently bought just because the vendor never updates it, which means those banks and things can't in practice demand that people do that. Indeed, it creates the opposite problem, because installing a custom ROM on that device would give it a patched kernel but cause it to fail attestation, so what the attestation is actually doing is requiring those people to continue to use the vulnerable OS.
Are you sure that's true? The whole reason why modern Safetynet/Play Integrity uses HSM data where possible is that you can't spoof that with root (without a microcode bug). It does not trust the running OS by design
I just tried GrapheneOS's https://attestation.app/ on a stock Pixel, and all of the OS version info shows in the "hardware verified" section
First there is Android's attestation framework. That does actual hardware attestation, as used by GrapheneOS, and supported by literally no app whatsoever.
Then there is SafetyNet, now Play Integrity. Depending on what level of integrity checking is being done, this will do a combination of cursory surface-level software checks, delegation to the aforementioned hardware attestation framework, and several other checks.
Importantly, SafetyNet/Play Integrity rejects some devices that pass hardware attestation (e.g., Graphene OS), and accepts some devices that fail hardware attestation (fairphone, many cheaper devices with broken ROMs, etc).
e.g., fairphone leaked the private key for their attestation, but many of their devices still pass SafetyNet, while some other devices that pass attestation but have known bootloader flaws are blocked by SafetyNet.
Because this isn't strict cryptographic verification, but a mess of heuristics and guesswork, it's a constant cat and mouse game.
What Google really achieved here is to make it expensive enough that no casual user can bypass it to e.g. cheat in Pokemon Go, but only a determined attacker has a chance.
And with "determined attacker" I'm not just talking about states, but even e.g. movie pirates breaking DRM to rip Netflix movies.
Of course, even full cryptographic attestation isn't perfect, and can be bypassed with enough effort. As shown by the famous iPhone hardware jailbreak, where you drill into the SoC and solder directly to the CPU's internal wiring.
Any app that can run native code execution on any version of Linux in the past fifteen years can get root until kernel updates arrive on your devices.
I tried using this for LPE on a Rocky9 for a couple of hours and thankfully couldn't get it to work. So that means unless you have quite some free time on your hand, or are extremely good at doing what you do, you can't actually use this to get LPE on enterprise distros.
The reason I re-upped this post, btw, is that it was at the top of a list called "underwater" that we try to look at every day, which lists the most-upvoted posts that for whatever reason didn't happen to make the frontpage. This was at the top of that list.
Messing with the displayed times people sent their comments is honestly akin to rewriting their answers.
Claude-ism detected. IME with Claude Code an object does not have a type or definition, apparently, but rather a shape (or at least it reaches for that word before more technically-accurate ones). Problems are not of a similar class or type, but of the same shape. Functions are not defined by their signatures but by their shape. Who talks like this and how did it make its way into the training data so pervasively?
I don't mean that as a criticism—the question of how to receive AI-processed content is chaotic right now. I'm working on a post about that here: https://news.ycombinator.com/item?id=48887149.
Btw, Nebula Sec is a YC startup in the current batch. We've been working with them on how to launch on HN, and one of the things I've been trying to explain is that the HN audience won't respond well to LLM-generated reports. The underlying work, though, is impressive. These guys know what they're doing—the OP is by no means their only significant find—and the fact that they're doing it with an agent, rather than the traditional way, is significant.
Obviously this is only one signal among many, one that can be overruled, but the ick remains regardless.
For example, non-native English speakers (as is the case with these guys IIRC) frequently use these tools. Maybe they shouldn't—as I've been telling a lot of people who email, mistakes are rapidly becoming a sign of authenticity at this point—but the belief that they need to is widespread, and this doesn't mean they didn't do significant work.
(Side note: it's a common assumption that machine-translated text is in a different category from LLM-edited text. From what we're seeing, that assumption is unfortunately wrong.)
Another important case is people with disabilities who find these technologies assistive. Again, one can argue that they're increasingly better off just posting their own writing in the raw, but this is a pretty obscure point to get across to people, and in some cases it would impose a significant burden.
Beyond those cases, a lot of people just don't write easily, and/or don't feel their writing is any good. A lot of them are using LLMs to compensate for that, and this by no means implies that their work is bad. Maybe they just have a phobia about writing and/or don't express themselves well that way.
People who enjoy writing or are confident writers fail to understand how emotionally fraught writing is for many others.
Personally I'm down with the "writing is thinking" view, from which it follows that bad writing is bad thinking. But it doesn't follow that "thinking is writing" - that's a much stronger claim, from which it would follow that good thinking is good writing—and this I think is false.
If one doesn’t put effort in their writing, I am not going to put effort to read whatever slop they put out instead. Simple as that.
That may sound like too fine a distinction, but it isn't. Here's an example: Show HN: Getting GLM 5.2 running on my slow computer - https://news.ycombinator.com/item?id=48842459, which was the #1 thread on HN a couple days ago (https://news.ycombinator.com/front?day=2026-07-09).
That user is a non-native English speaker who helped get his posts into a format that HN could appreciate. His work is obviously excellent—the community response was unambiguous. But I don't think it would have made it through without our help.
I'm sure you weren't saying that if someone can't describe their work in good English then it must be slop, but the space is larger than you make it sound. Which is unfortunate in a way—it would be easier to narrow it down, but then we'd miss posts like that one.
Perhaps it was this: there are many non-native English speakers who have valuable things to contribute to HN, who don't yet have sufficient English or don't feel they do, and therefore resort to LLMs to do their English for them. Should they automatically be excluded?
If you mean the linked content: can come from anyone and anywhere--it's just whatever someone submits and is deemed good enough by The Algorithm to get attention. So that's not "HN content" - the content exists independently of HN. As for that, I'll repeat myself: the scientific community has managed somehow to intercommunicate for centuries despite language barriers before LLMs existed. (English was neither Einstein's nor Madame Curie's first language.) It's an existence proof that LLMs aren't needed to overcome those barriers.
https://www.marginalia.nu/log/40-wasted-resources/
and even more similar usage again in 2023 'the shape of the algorithm' (which was post-claude I guess, but this was before I even tested any LLM):
I'm not a grammatical prescriptivist but I find it viscerally troubling that a bunch of LLM cargo-culted terms are starting to inform how we talk about our work.
https://blog.jle.im/entry/functors-to-monads-a-story-of-shap...
It's not so widely used and it's not explained in the first couple screenfuls of TFA (which by itself is weirdly structured, taking entire paragraphs to explain when it was introduced, when it was discovered, etc. before even explaining what it actually is).
Of course the title was chosen when the article was first published on a site dedicated to security, where probably everyone knows it. This suggests that insisting on unmodified titles when republishing in HN is a poor rule.
Maybe just Algol68 and Rust can withstand this, among ADA. And PL/1 under Multics.
It was even enumerated in the first pass of CWE as CWE-416 in 2006.
There is a lot of cool work that went into making memory allocation work well; the different arenas, fast bins, chunk headers, etc. are super cool.
"Use after free" is also described in most standard books about C as a thing you should never do, have you read one?
The idea that Claude came up with it is ridiculous.
2025: https://redis.io/blog/security-advisory-cve-2025-49844/ 2023: https://seclists.org/oss-sec/2023/q2/133 2022: https://www.zerodayinitiative.com/advisories/ZDI-22-1690/ 2014: https://ftp.openbsd.org/pub/OpenBSD/patches/5.4/common/008_o...
It's an issue as old as time, or thereabouts.
Also can we talk about how bad Linux security is? At this point it's becoming a real liability to run anything on Linux that needs to be secure. OpenBSD has been around for ages, is written in C, and is really, really secure. Do they support containers yet (or microVMs)? Cuz if they do, I'm moving my workloads to obsd.
Why are you not making easy money hand over fist from these rewards? A couple of weekends of work and you can retire early.
Maybe that's exactly what these infosec companies are. And maybe you need more than "a skid with claude over a weekend" to get anything worthwhile.
I don't see any ports dependency issues as there's been binary packages available forever. Even the install process is a lot faster than any linux I have to use at $work, not to mention easier to automate with autoinstall[0] if needed.
There are many issues with the formulation of containers on Linux (though I think people overstate it whenever bugs like this happen) but ultimately this bug was a UAF that gave you arbitrary code execution in the kernel. Zone IDs are also just numbers in kernel memory... right?
[0]https://www.usenix.org/legacy/event/lisa04/tech/full_papers/...
[1]Tape different things together and see if it holds.
(I've been one of the maintainers of runc -- the most widely use used container runtime on Linux -- for more than a decade, so I'm at least somewhat well-informed on the topic.)
The duct tape criticisms are fair when talking about other vulnerabilities (such as when container runtimes have misconfiguration or other inatomicity bugs) but not really here in the context of a kernel arbitrary code execution gadget. It also seems quite unlikely that the illumos kernel doesn't contain any of these kinds of bugs.
... until its getting popular usage and gets targeted for vulnerability research