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Search - "arp"
Navy story time again. Grab that coffee and fire up Kali, the theme is security.
So, when I got promoted to Lieutenant Jr. I had to attend a 1-year school inside my nostalgic Naval Academy... BUT! I was wiser, I was older... and I was bored. Like, really bored. What could go wrong? Well, all my fellow officers were bored too, so they started downloading/streaming/torrenting like crazy, and I had to wait for hours for the Kali updates to download, so...
mdk3 wlan0mon -d
I had this external wifi atheros card with two antennae and kicked all of them off the wifi. Some slightly smarter ones plugged cables on the net, and kept going, enjoying much faster speeds. I had to go to the bathroom, and once I returned they had unplugged the card. That kind of pissed me off, since they also thought it would be funny to hide it, along with the mouse.
But, oh boy, they had no idea what supreme asshole I can be when I am irked.
So, arpspoof it is. Turns out, there were no subnetworks, and the broadcast domain was ALL of the academy. That means I shut EVERYONE off, except me. Hardware was returned in 1 minute with the requested apologies, but fuck it, I kept the whole academy off the net for 6 hours. The sysadmin ran around like crazy, because nothing was working. Not even the servers.
I finally took pity on the guy (he had gotten the duties of sysadmin when the previous sysad died, so think about that) and he almost assaulted me when I told him. As it turned out, the guy never had any training or knowledge on security, so I had to show him a few things, and point him to where he could study about the rest. But still, some selective arp poison on select douchebags was in order...
Needless to say, people were VERY polite to me after that. And the net speed was up again, so I got bored. Again. So I started scanning the net.
To be continued...3
Navy story continued.
And continuing from the arp poisoning and boredom, I started scanning the network...
So I found plenty of WinXP computers, even some Win2k servers (I shit you not, the year was 201X) I decided to play around with merasploit a bit. I mean, this had to be a secure net, right?
Like hell it was.
Among the select douchebags I arp poisoned was a senior officer that had a VERY high idea for himself, and also believed he was tech-savvy. Now that, is a combination that is the red cloth for assholes like me. But I had to be more careful, as news of the network outage leaked, and rumours of "that guy" went amok, but because the whole sysadmin thing was on the shoulders of one guy, none could track it to me in explicit way. Not that i cared, actually, when I am pissed I act with all the subtleness of an atom bomb on steroids.
So, after some scanning and arp poisoning (changing the source MAC address this time) I said...
"Let's try this common exploit, it supposedly shouldn't work, there have been notifications about it, I've read them." Oh boy, was I in for a treat. 12 meterpreter sessions. FUCKING 12. The academy's online printer had no authentication, so I took the liberty of printing a few pages of ASCII jolly rogers (cute stuff, I know, but I was still in ITSec puberty) and decided to fuck around with the other PCs. One thing I found out is that some professors' PCs had the extreme password of 1234. Serious security, that was. Had I known earlier, I could have skipped a TON of pointless memorising...
Anyway, I was running amok the entire network, the sysad never had a chance on that, and he seemed preoccupied with EVERYTHING ELSE besides monitoring the net, like fixing (replacing) the keyboard for the commander's secretary, so...
BTW, most PCs had antivirus, but SO out of date that I didn't even need to encode the payload or do any other trick. An LDAP server was open, and the hashed admin password was the name of his wife. Go figure.
I looked at a WinXP laptop with a weird name, and fired my trusty ms08_067 on it. Passowrd: "aaw". I seriously thought that Ophcrack was broken, but I confirmed it. WTF? I started looking into the files... nothing too suspicious... wait a min, this guy is supposed to work, why his browser is showing porn?
Looking at the ""Deleted"" files (hah!) I fount a TON of documents with "SECRET" in them. Curious...
Decided to download everything, like the asshole I am, and restart his PC, AND to leave him with another desktop wallpaper and a text message. Thinking that he took the hint, I told the sysadmin about the vulnerable PCs and went to class...
In the middle of the class (I think it was anti-air warfare or anti-submarine warfare) the sysad burst through the door shouting "Stop it, that's the second-in-command's PC!".
Stunned silence. Even the professor (who was an officer). God, that was awkward. So, to make things MORE awkward (like the asshole I am) I burned every document to a DVD and the next day I took the sysad and went to the second-in-command of the academy.
Surprisingly he took the whole thing in quite the easygoing fashion. I half-expected court martial or at least a good yelling, but no. Anyway, after our conversation I cornered the sysad and barraged him with some tons of security holes, needed upgrades and settings etc. I still don't know if he managed to patch everything (I left him a detailed report) because, as I've written before, budget constraints in the military are the stuff of nightmares. Still, after that, oddly, most people wouldn't even talk to me.
God, that was a nice period of my life, not having to pretend to be interested about sports and TV shows. It would be almost like a story from highschool (if our highschool had such things as a network back then - yes, I am old).
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?10
Long rant ahead.. so feel free to refill your cup of coffee and have a seat 🙂
It's completely useless. At least in the school I went to, the teachers were worse than useless. It's a bit of an old story that I've told quite a few times already, but I had a dispute with said teachers at some point after which I wasn't able nor willing to fully do the classes anymore.
So, just to set the stage.. le me, die-hard Linux user, and reasonably initiated in networking and security already, to the point that I really only needed half an ear to follow along with the classes, while most of the time I was just working on my own servers to pass the time instead. I noticed that the Moodle website that the school was using to do a big chunk of the course material with, wasn't TLS-secured. So whenever the class begins and everyone logs in to the Moodle website..? Yeah.. it wouldn't be hard for anyone in that class to steal everyone else's credentials, including the teacher's (as they were using the same network).
So I brought it up a few times in the first year, teacher was like "yeah yeah we'll do it at some point". Shortly before summer break I took the security teacher aside after class and mentioned it another time - please please take the opportunity to do it during summer break.
Coming back in September.. nothing happened. Maybe I needed to bring in more evidence that this is a serious issue, so I asked the security teacher: can I make a proper PoC using my machines in my home network to steal the credentials of my own Moodle account and mail a screencast to you as a private disclosure? She said "yeah sure, that's fine".
Pro tip: make the people involved sign a written contract for this!!! It'll cover your ass when they decide to be dicks.. which spoiler alert, these teachers decided they wanted to be.
So I made the PoC, mailed it to them, yada yada yada... Soon after, next class, and I noticed that my VPN server was blocked. Now I used my personal VPN server at the time mostly to access a file server at home to securely fetch documents I needed in class, without having to carry an external hard drive with me all the time. However it was also used for gateway redirection (i.e. the main purpose of commercial VPN's, le new IP for "le onenumity"). I mean for example, if some douche in that class would've decided to ARP poison the network and steal credentials, my VPN connection would've prevented that.. it was a decent workaround. But now it's for some reason causing Moodle to throw some type of 403.
Asked the teacher for routers and switches I had a class from at the time.. why is my VPN server blocked? He replied with the statement that "yeah we blocked it because you can bypass the firewall with that and watch porn in class".
Alright, fair enough. I can indeed bypass the firewall with that. But watch porn.. in class? I mean I'm a bit of an exhibitionist too, but in a fucking class!? And why right after that PoC, while I've been using that VPN connection for over a year?
Not too long after that, I prematurely left that class out of sheer frustration (I remember browsing devRant with the intent to write about it while the teacher was watching 😂), and left while looking that teacher dead in the eyes.. and never have I been that cold to someone while calling them a fucking idiot.
Shortly after I've also received an email from them in which they stated that they wanted compensation for "the disruption of good service". They actually thought that I had hacked into their servers. Security teachers, ostensibly technical people, if I may add. Never seen anyone more incompetent than those 3 motherfuckers that plotted against me to save their own asses for making such a shitty infrastructure. Regarding that mail, I not so friendly replied to them that they could settle it in court if they wanted to.. but that I already knew who would win that case. Haven't heard of them since.
So yeah. That's why I regard those expensive shitty pieces of paper as such. The only thing they prove is that someone somewhere with some unknown degree of competence confirms that you know something. I think there's far too many unknowns in there.
Nowadays I'm putting my bets on a certification from the Linux Professional Institute - a renowned and well-regarded certification body in sysadmin. Last February at FOSDEM I did half of the LPIC-1 certification exam, next year I'll do the other half. With the amount of reputation the LPI has behind it, I believe that's a far better route to go with than some random school somewhere.27
One of my CSC friends never ceases to amaze me. He built a "Roommate Tracker" so that whenever he wants to see who's at the apartment, he can check without having to bother anyone.
The kicker is that the thing runs by taking advantage of ARP requests and a always-on device's ARP table. iPhones and a few other devices don't respond to many network request when they sleep, but you can bet they respond to ARP!
So he wrote some code, the device keeps some log files, and then be displays it all in a web server he can access wherever. All to figure out when certain people's devices are present, active, or gone elsewhere!
👌👌👌 A+ for ingenuity (and over-engineering).8
This was a long time ago, when I was working part time in my uni helpdesk. as part of the uni IT service, they offered ISP services at the dorms. It was cheap, and fast. This essentially allowed students living in the dorms to connect thier personal computers to the uni LAN. Then one day...
An ARP poison malware infected some of those computers. An arp poison attack is simple (look at ettercap) - it redirects network traffic via the affected computer, and adds malware to webtraffic to infect more computers. One of these on a network is bad enough, but when there more then one... traffic was redirected a lot. this caused the Dorm switches to collapse under the load. Fun times to work at the helpdesk...
The IT guys came up with a solution for this: they blocked the arp poision attacks at the firewall, and then disabled the switch port for the infected computer for 24 hours. so, when someone called with 'I have no internet!', we told them to bring us the computer, and installed an AV on it.
3-4 month the problem was cleared.1
💻 Four months ago. 💻
The Systems & Networks's professor said "You've to do a program that simulate the ARP table, in C."
After one week I had done the program!😎 (About 400 code lines)
And the rest of the class?
... One week... Two week... Three week.
Somebody had done the program, somebody else no.
Have an "informatics-stupid class" is funny and makes you look smarter. 😂🔝