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https://git.kernel.org/…/ke…/... sure some of you are working on the patches already, if you are then lets connect cause, I am an ardent researcher for the same as of now.
So here it goes:
As soon as kernel page table isolation(KPTI) bug will be out of embargo, Whatsapp and FB will be flooded with over-night kernel "shikhuritee" experts who will share shitty advices non-stop.
1. The bug under embargo is a side channel attack, which exploits the fact that Intel chips come with speculative execution without proper isolation between user pages and kernel pages. Therefore, with careful scheduling and timing attack will reveal some information from kernel pages, while the code is running in user mode.
In easy terms, if you have a VPS, another person with VPS on same physical server may read memory being used by your VPS, which will result in unwanted data leakage. To make the matter worse, a malicious JS from innocent looking webpage might be (might be, because JS does not provide language constructs for such fine grained control; atleast none that I know as of now) able to read kernel pages, and pawn you real hard, real bad.
2. The bug comes from too much reliance on Tomasulo's algorithm for out-of-order instruction scheduling. It is not yet clear whether the bug can be fixed with a microcode update (and if not, Intel has to fix this in silicon itself). As far as I can dig, there is nothing that hints that this bug is fixable in microcode, which makes the matter much worse. Also according to my understanding a microcode update will be too trivial to fix this kind of a hardware bug.
3. A software-only remedy is possible, and that is being implemented by all major OSs (including our lovely Linux) in kernel space. The patch forces Translation Lookaside Buffer to flush if a context switch happens during a syscall (this is what I understand as of now). The benchmarks are suggesting that slowdown will be somewhere between 5%(best case)-30%(worst case).
4. Regarding point 3, syscalls don't matter much. Only thing that matters is how many times syscalls are called. For example, if you are using read() or write() on 8MB buffers, you won't have too much slowdown; but if you are calling same syscalls once per byte, a heavy performance penalty is guaranteed. All processes are which are I/O heavy are going to suffer (hostings and databases are two common examples).
5. The patch can be disabled in Linux by passing argument to kernel during boot; however it is not advised for pretty much obvious reasons.
6. For gamers: this is not going to affect games (because those are not I/O heavy)
Meltdown: "Meltdown" targeted on desktop chips can read kernel memory from L1D cache, Intel is only affected with this variant. Works on only Intel.
Spectre: Spectre is a hardware vulnerability with implementations of branch prediction that affects modern microprocessors with speculative execution, by allowing malicious processes access to the contents of other programs mapped memory. Works on all chips including Intel/ARM/AMD.
For updates refer the kernel tree: https://git.kernel.org/…/ke…/...
For further details and more chit-chats refer: https://lwn.net/SubscriberLink/...
~Cheers~
(Originally written by Adhokshaj Mishra, edited by me. )
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3 rants for the price of 1, isn't that a great deal!
1. HP, you braindead fucking morons!!!
So recently I disassembled this HP laptop of mine to unfuck it at the hardware level. Some issues with the hinge that I had to solve. So I had to disassemble not only the bottom of the laptop but also the display panel itself. Turns out that HP - being the certified enganeers they are - made the following fuckups, with probably many more that I didn't even notice yet.
- They used fucking glue to ensure that the bottom of the display frame stays connected to the panel. Cheap solution to what should've been "MAKE A FUCKING DECENT FRAME?!" but a royal pain in the ass to disassemble. Luckily I was careful and didn't damage the panel, but the chance of that happening was most certainly nonzero.
- They connected the ribbon cables for the keyboard in such a way that you have to reach all the way into the spacing between the keyboard and the motherboard to connect the bloody things. And some extra spacing on the ribbon cables to enable servicing with some room for actually connecting the bloody things easily.. as Carlos Mantos would say it - M-m-M, nonoNO!!!
- Oh and let's not forget an old flaw that I noticed ages ago in this turd. The CPU goes straight to 70°C during boot-up but turning on the fan.. again, M-m-M, nonoNO!!! Let's just get the bloody thing to overheat, freeze completely and force the user to power cycle the machine, right? That's gonna be a great way to make them satisfied, RIGHT?! NO MOTHERFUCKERS, AND I WILL DISCONNECT THE DATA LINES OF THIS FUCKING THING TO MAKE IT SPIN ALL THE TIME, AS IT SHOULD!!! Certified fucking braindead abominations of engineers!!!
Oh and not only that, this laptop is outperformed by a Raspberry Pi 3B in performance, thermals, price and product quality.. A FUCKING SINGLE BOARD COMPUTER!!! Isn't that a great joke. Someone here mentioned earlier that HP and Acer seem to have been competing for a long time to make the shittiest products possible, and boy they fucking do. If there's anything that makes both of those shitcompanies remarkable, that'd be it.
2. If I want to conduct a pentest, I don't want to have to relearn the bloody tool!
Recently I did a Burp Suite test to see how the devRant web app logs in, but due to my Burp Suite being the community edition, I couldn't save it. Fucking amazing, thanks PortSwigger! And I couldn't recreate the results anymore due to what I think is a change in the web app. But I'll get back to that later.
So I fired up bettercap (which works at lower network layers and can conduct ARP poisoning and DNS cache poisoning) with the intent to ARP poison my phone and get the results straight from the devRant Android app. I haven't used this tool since around 2017 due to the fact that I kinda lost interest in offensive security. When I fired it up again a few days ago in my PTbox (which is a VM somewhere else on the network) and today again in my newly recovered HP laptop, I noticed that both hosts now have an updated version of bettercap, in which the options completely changed. It's now got different command-line switches and some interactive mode. Needless to say, I have no idea how to use this bloody thing anymore and don't feel like learning it all over again for a single test. Maybe this is why users often dislike changes to the UI, and why some sysadmins refrain from updating their servers? When you have users of any kind, you should at all times honor their installations, give them time to change their individual configurations - tell them that they should! - in other words give them a grace time, and allow for backwards compatibility for as long as feasible.
3. devRant web app!!
As mentioned earlier I tried to scrape the web app's login flow with Burp Suite but every time that I try to log in with its proxy enabled, it doesn't open the login form but instead just makes a GET request to /feed/top/month?login=1 without ever allowing me to actually log in. This happens in both Chromium and Firefox, in Windows and Arch Linux. Clearly this is a change to the web app, and a very undesirable one. Especially considering that the login flow for the API isn't documented anywhere as far as I know.
So, can this update to the web app be rolled back, merged back to an older version of that login flow or can I at least know how I'm supposed to log in to this API in order to be able to start developing my own client?6 -
I hate buying new laptops. HATE IT. The manufacturers are always trying to do something that makes it more complicated to buy a laptop confidently.
Why not name all of the laptops with numbers? Make them really hard to differentiate. Then offer the same model number across multiple years so it is difficult to determine which year the laptop is from.
Oh. And let’s make sure every laptop has a major flaw in the form factor.
Let’a add a numpad that squishes the keyboard to the left in a weird way. Lets do something to the trackpad to make it awkward to use. Maybe the keyboard should have a weird configuration. Maybe we can put 4 spare characters of various colours on the symbol key caps. How about a battery only lasts a few hours. May we add specialized hardware so you are stuck with windows. Maybe we can make it super thick and heavy. Lets have a screen with terrible viewing angles. Since this laptop has no major flaws we should overprice it. No repairs or upgrades on this one because we filled the computer with glue. Lets double the amount of useless media keys.
It is like manufacturers are trying to design laptops like RPG game character classes. The fighter has no magic or stealth. The magician is weak and gets fatigued. The rogue is very stealthy but has poor defence and attack. The cleric can use magic but only to heal so it is useless in battle. The ranger is good at distance but has poor defence and no magic.
The only notebooks sold that are trying to make balanced character classes are MacBooks. Those cost a premium and aren’t reparable.17
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