frontpage.
newsnewestaskshowjobs

Made with ♥ by @iamnishanth

Open Source @Github

fp.

Open in hackernews

RCE via ND6 Router Advertisements in FreeBSD

https://www.freebsd.org/security/advisories/FreeBSD-SA-25:12.rtsold.asc
42•weeha•3h ago

Comments

imvetri•3h ago
is my understanding right?

"PC or computers or hardware that uses OS that consume FreeBSD, has a faulty software for the router's firmware?"

"The router's software performs ad distributions?"

"The version of internet, the router uses, is updated, whereas, the target machine, or the user's machine is still running a old version"

"The security patch works for the modern but not the precursor version?"

"This leaves older systems obsolete in the market?"

"is this a step-by-step instructions to business owners to introduce new products, selling that older products are obsolete" ?

eptcyka•2h ago
No, I don't think you are understanding this right, but there are some good questions you are asking. Where is the flag button?

If you are a real human, the most interesting question you're bringing up is What about all the appliances backed by FreeBSD? Yes, they are obsolete if they use IPv6 and accept RAs and if they don't get updates.

jacquesm•2h ago
That was my first thought, if this is an embedded system without an update path this will be super hard to solve. People usually are not even aware of what OS their appliances run under the hood and whether or not they are updated automatically and how to update them if they are not.
jacquesm•2h ago
Oh that's a nasty one, embedded FreeBSD users will have a hard time mitigating this.
formerly_proven•2h ago
Free jailbreaks for everyone though!
jacquesm•2h ago
We had a soccer player in NL that was wildly popular and he had these funny remarks every now and then which got him nicknamed the most well known dutch philosopher. One of these was 'every advantage has its disadvantage', I guess this is one of those.
tecleandor•58m ago
Ha! He was famous for that even when coaching in Spain
TekMol•2h ago

    vulnerable to remote code execution from
    systems on the same network segment
Isn't almost every laptop these days autoconnecting to known network names like "Starbucks" etc, because the user used it once in the past?

That would mean that every FreeBSD laptop in proximity of an attacker is vulnerable, right? Since the attacker could just create a hotspot with the SSID "Starbucks" on their laptop and the victim's laptop will connect to it automatically.

francasso•2h ago
If you run FreeBSD on your laptop you don't auto connect to public WiFi.

Joking, but not that much :)

badgersnake•2h ago
Your wifi chip probably isn’t supported tbh.
keyle•1h ago
This is the real joke.
BSDobelix•1h ago
FreeBSD 15 had a massive improvement with WiFi, however if you let your Computer auto-connect to a "unknown" Network...well that's not good.
TekMol•53m ago
My question was about known networks.

As far as I know, access points only identify via their SSID. Which is a string like "Starbucks". So there is no way to tell if it is the real Starbucks WiFi or a hotspot some dude started on their laptop.

BSDobelix•51m ago
>So there is no way to tell if it is the real Starbucks WiFi or a hotspot some dude started on their laptop.

Aka "unknown" or "public" Network....don't do that.

evandrofisico•34m ago
WPA2-entreprise and WPA3 both have certificate chains checking exactly to avoid such attacks
hhh•2h ago
dozens of people will be affected
rs_rs_rs_rs_rs•2h ago
IPv6 is a prerequisite for the bug to be exploited, it won't affect anyone.
ale42•2h ago
Why, is IPv6 activation manual in FreeBSD?
rs_rs_rs_rs_rs•2h ago
It's enabled by default, I was mostly talking about being in a lan with active ipv6, imo that's not that common.
shakna•2h ago
That's pretty standard where I am. Every Telstra router comes with IPv6 enabled.
immibis•1h ago
As it should be. If your ISP isn't giving you ipv6, they're not giving you internet access and you should sue for your money back.
ale42•2h ago
IMHO you do not need "active" IPv6. Most LANs (unless you have some switch-level filtering that blocks router advertisements from "unauthorized" nodes) can transport such IPv6 packets. Then it just takes being connected to the LAN and being able to send an arbitrary ICMP6 packet (which probably means being root on the attacker machine, not a very high barrier I'd say).
BSDobelix•1h ago
No, you can choose if you want IPv4 or IPv6 or both, at installation time also if you want it in "autoconf-mode"
tuetuopay•1h ago
Can we be done with the house of cards that are shell scripts everywhere?

Anyways, this feels like a big issue for "hidden" FreeBSD installs, like pfSense or TrueNAS (if they are still based on it though). Or for servers on hosting providers where they share a LAN with their neighbors in the same rack.

And it's a big win for jailbreaking routers :D

wahern•1h ago
Sure, as long as the solution isn't to just bolt on another distinct DNS monolith. The root of the problem IMO is that no libc, AFAIK, exports an API for parsing, let alone composing or manipulating, resolv.conf formatted data. The solutions have either been the same as FreeBSD (openresolv, a portable implementation of Debian's resolvconf tool), or just freezing resolv.conf (notwithstanding occassional new libc features) and bolting atop (i.e. keeping in place) the existing infrastructure a monolithic resolver service with their own bespoke configs, such as macOS and Linux/systemd have done. But resolv.conf can never go away, because it's the only sane and portable way for your average userland program to load DNS configuration, especially async resolver libraries.

It's a coordination problem. Note that the original notion of resolvconf, IIUC, was it was only stitching together trusted configuration data. That's no excuse, of course, for not rigorously isolating data from execution, which is more difficult in shell scripts--at least, if you're not treating the data as untrusted from the get go. It's not that difficult to write shell code to handle untrusted data, you just can't hack it together without keeping this is mind. And it would be much easier if the resolver infrastructure in libc had a proper API for dealing with resolv.conf (and others), which could be exported by a small utility which in turn could be used to slice and dice configurations from shell scripts.

The problem with the new, alternative monoliths is they very quickly run off into the weeds with their crazy features and configuration in ways that create barriers for userland applications and libraries to rely upon, beyond bootstrapping them to query 127.0.0.1:53. At the end of the day, resolv.conf can never really go away. So the proper solution, IMO, is to begin to carefully build layers around the one part that we know for a fact won't go away, rather than walking away with your ball to build a new playground. But that requires some motivated coordination and cooperation with libc developers.

tuetuopay•48m ago
> Sure, as long as the solution isn't to just bolt on another distinct DNS monolith

Why not? And I don't mean this in tongue-in-cheek, but as a genuine interrogation: why not go the macOS/systemd route?

DNS is a complex topic. Much more complex than people admit it is, and that can definitely not be expressed fully with resolv.conf. I do agree that it is too late to get rid of it (and was not my concern actually), but it is too limited to be of actual use outside of the simple "I have a single DNS server with a single search domain". IMHO, a dedicated local daemon with its own bespoke config definitely has value, even if it solely provides a local cache for applications that don't have one already (like most of them outside of browsers). And for more complex cases, simple integration with the network configuration daemon provides actual value in e.g. knowing that a specific server is reachable through a specific interface that has a specific search domain. That is, native routing to the correct servers to avoid the timeout dance as soon as you have split networks.

Also, for the local ad-hoc configuration part. We already have nsswitch which is its own can of worms that pretty much nobody have ever heard about let even touched its configuration. Heck, I've written DNS servers but only looked once at nsswitch. resolved's configuration is integrated in the systemd ecosystem, has an approachable and well documented configuration, and is pretty useful in general.

Anyways, the main gripe I had was not really at the mess that is DNS on Linux, but the general stance in the UNIX-like world against anything that's not a lego of shell scripts because "that's not the unix philosophy". Yeah you can write an init system fully with sh, have their "units" also all be written in sh, but oh lord has stuff like systemd improved the situation for the init + service part. Having a raw string from a network packet land in a shell script is a recipe for disaster, seeing how much quoting in scripts is famously difficult.

> The problem with the new, alternative monoliths is they very quickly run off into the weeds with their crazy features and configuration

Agreed for the crazy features. systemd is a godsend for the modern linux world, but I'm skeptical when I see the likes of systemd-home. Yet the configuration is not where I'd pick at those systems though, because they tend to be much more configurable. They are opiniated, yes, but the configuration is an actual configuration and not a patchwork of shell scripts somewhere in /etc, when they're not direct patches to the foundational shell scripts!

> in ways that create barriers for userland applications

How so? In the specific example of resolved, I'd argue it's even less work for applications, because they don't need to query multiple DNS servers at once (it'll handle it for them), don't need to try resolution with and without search domain, etc.

In the end, I find that resolved's approach at symlinking its stub resolv.conf is the most elegant approach with our current setups.

PS: I talk a lot about resolved because that's the one I know best, not the one I think is the best! It has loads of shortcomings too, yet it's still a net improvement to whatever was in place before.

wahern•1h ago
Is somebody fuzzing IPv6 autoconfiguration stacks? OpenBSD published an nd6 kernel fix earlier this month for an unrelated issue: https://ftp.openbsd.org/pub/OpenBSD/patches/7.8/common/011_n...
clan•39m ago
This actually makes me happy! I must be getting old!

It truly is a bad one but I really appreciate Kevin Day for finding/reporting this and for all the volunteer work fixing this.

All I had to do was "freebsd-update fetch install && reboot" on my systems and I could continue my day. Fleet management can be that easy for both pets and cattle. I do however feel for those who have deployed embedded systems. We can only hope the firmware vendors are on top of their game.

My HN addiction is now vindicated as I would probably not have noticed this RCE until after christmas.

This makes me very grateful and gives me a warm fuzzy feeling inside!

chaz6•11m ago
Having a shell script in the code path that processes router advertisements seems sub-optimal.

After Ruining a Treasured Water Resource, Iran Is Drying Up

https://e360.yale.edu/features/iran-water-drought-dams-qanats
61•YaleE360•1h ago•21 comments

How getting richer made teenagers less free

https://www.theargumentmag.com/p/how-getting-richer-made-teenagers
90•NavinF•1h ago•64 comments

It's all about momentum

https://combo.cc/posts/its-all-about-momentum-innit/
28•sph•1h ago•3 comments

Slowness Is a Virtue

https://blog.jakobschwichtenberg.com/p/slowness-is-a-virtue
23•jakobgreenfeld•1h ago•5 comments

RCE via ND6 Router Advertisements in FreeBSD

https://www.freebsd.org/security/advisories/FreeBSD-SA-25:12.rtsold.asc
42•weeha•3h ago•29 comments

What is an elliptic curve? (2019)

https://www.johndcook.com/blog/2019/02/21/what-is-an-elliptic-curve/
81•tzury•5h ago•7 comments

Egyptian Hieroglyphs: Lesson 1

https://www.egyptianhieroglyphs.net/egyptian-hieroglyphs/lesson-1/
69•jameslk•5h ago•15 comments

Gemini 3 Flash: Frontier intelligence built for speed

https://blog.google/products/gemini/gemini-3-flash/
998•meetpateltech•19h ago•528 comments

Online Textbook for Braid groups and knots and tangles

https://matthematics.com/redoak/redoak.html
13•marysminefnuf•2h ago•0 comments

Jonathan Blow has spent the past decade designing 1,400 puzzles for you

https://arstechnica.com/gaming/2025/12/jonathan-blow-has-spent-the-past-decade-designing-1400-puz...
89•furcyd•6d ago•60 comments

Coursera to combine with Udemy

https://investor.coursera.com/news/news-details/2025/Coursera-to-Combine-with-Udemy-to-Empower-th...
526•throwaway019254•23h ago•316 comments

GitHub Actions for Self-Hosted Runners Price Increase Postponed

https://pricetimeline.com/news/189
64•taubek•3h ago•40 comments

I got hacked: My Hetzner server started mining Monero

https://blog.jakesaunders.dev/my-server-started-mining-monero-this-morning/
433•jakelsaunders94•14h ago•282 comments

Working quickly is more important than it seems (2015)

https://jsomers.net/blog/speed-matters
183•bschne•3d ago•94 comments

Creating apps like Signal could be 'hostile activity' claims UK watchdog

https://www.techradar.com/vpn/vpn-privacy-security/creating-apps-like-signal-or-whatsapp-could-be...
10•donohoe•33m ago•2 comments

Building a High-Performance OpenAPI Parser in Go

https://www.speakeasy.com/blog/building-speakeasy-openapi-go-library
16•subomi•3d ago•4 comments

Breaking Paragraphs into Lines [pdf] (1981)

https://gwern.net/doc/design/typography/tex/1981-knuth.pdf
10•Smaug123•5d ago•4 comments

Ask HN: Those making $500/month on side projects in 2025 – Show and tell

274•cvbox•10h ago•250 comments

America's Dirtiest Carbon Polluters, Mapped to Ridiculous Precision

https://gizmodo.com/americas-dirtiest-carbon-polluters-mapped-to-ridiculous-precision-2000700924
13•ourmandave•53m ago•1 comments

Gut bacteria from amphibians and reptiles achieve tumor elimination in mice

https://www.jaist.ac.jp/english/whatsnew/press/2025/12/17-1.html
416•Xunxi•12h ago•101 comments

Don MacKinnon: Why Simplicity Beats Cleverness in Software Design [audio]

https://maintainable.fm/episodes/don-mackinnon-why-simplicity-beats-cleverness-in-software-design
47•mooreds•2d ago•16 comments

AWS CEO says replacing junior devs with AI is 'one of the dumbest ideas'

https://www.finalroundai.com/blog/aws-ceo-ai-cannot-replace-junior-developers
944•birdculture•18h ago•482 comments

We Let AI Run Our Office Vending Machine. It Lost Hundreds of Dollars

https://www.wsj.com/tech/ai/anthropic-claude-ai-vending-machine-agent-b7e84e34
12•lukaspetersson•1h ago•4 comments

Judge hints Vizio TV buyers may have rights to source code licensed under GPL

https://www.theregister.com/2025/12/05/vizio_gpl_source_code_ruling/
109•pabs3•7h ago•13 comments

A Safer Container Ecosystem with Docker: Free Docker Hardened Images

https://www.docker.com/blog/docker-hardened-images-for-every-developer/
329•anttiharju•18h ago•75 comments

Show HN: I built a fast RSS reader in Zig

https://github.com/superstarryeyes/hys
74•superstarryeyes•1d ago•23 comments

OBS Studio Gets a New Renderer

https://obsproject.com/blog/obs-studio-gets-a-new-renderer
261•aizk•14h ago•55 comments

'Ghost jobs' are on the rise – and so are calls to ban them

https://www.bbc.com/news/articles/clyzvpp8g3vo
136•1659447091•6h ago•145 comments

Tell HN: HN was down

571•uyzstvqs•19h ago•309 comments

Ask HN: Does anyone understand how Hacker News works?

115•jannesblobel•11h ago•143 comments