There are currently four computers in my household: a Windows 10 desktop, a Windows 11 laptop, and two additional Linux laptops (those are "mine"). One is a very weak but new machine, basically the cheapest laptop I could buy that was neither Android nor literally a toy. It is running Lubuntu 24.04, and is used largely for writing and light browsing. The other is an older machine running MX Linux. Right now it's single purpose is running my Plex server. Given that setup, transferring files between machines is often a necessity.

Both my desktop computer and my Plex server are connected via Ethernet directly to the router. The other two laptops are connected largely via WIFI, although I do connect my writing laptop via an USB/Ethernet adapter for updates/upgrades and larger downloads when necessary.

Among other things, I often download movies on my Windows 10 desktop computer and then manually transfer them in batches to my Plex external hard-drive, and then to my Plex laptop (when it has enough space, otherwise I just keep the movies on the hard-drive). That is because it is way more convenient for me to (re)search what I wish to wwatch, find and download it to my desktop than it would be the case for my Plex laptop. The laptop is not only in a position that makes it uncomfortable to use but is also very slow even for basic things such as firing up Firefox. I also prefer to do the scraping using MediaElch and while it is a fairly heavy (probably Electron) application, my desktop is powerful enought that it doesn't make any diference. I also use Subsync sometimes, which is, as far a I know, only available as a GUI application on Windows.

Most content I find online is very practical, teaching me how to follow concrete steps to make things work, but I haven't found much advice on which programs or tech "stack" would be adequate for a specific situation such as my own. I just want a robust way to seamlessly transfer file between all the machines on my home without having to plug and unplug hard-disks and flash drives.

Any suggestion? Thanks!

Hello good and clever people of Tildes, I need some advice.

With electricity the price it is, and my wife having a sizable workshop in the garden, I'm looking for ways to bring down the heating cost.

Her workshop is 5m x 4m x 2.2m, and the wood is 44cm thick. It's a chunky beast. She makes gifts and personalised items, so when she has the heatpresses and mug/tumbler press on the go, it gets toasty. If the sun comes out, also toasty. However, over night, it gets super chilled, almost to whatever temp is outside. To combat this I decided to use a Govee Electric Space Heater, 1500W with Thermostat, WiFi & Bluetooth. However, this barely does anything and the electric usage flies up.

What are good options here? The office is about 10 metres from my house. It's too far to extend the home central heating via plumbing, plus too much lagging. I don't want to spend a fortune, so any sensible options I'm willing to entertain. If we're talking a couple of thousand, it's off the menu.

Thanks for any help.

Dropping an edit with a link to the actual cabin: https://www.tigersheds.com/product/the-gamma-44mm-log-cabin/

It's not like a USA style log cabin, that's for sure!

Edit 2: Okay - wall insulation looks like the next thing to tackle before even thinking about heating it. Thanks folks.

[SOLVED]

... well, this is in many ways very unsatisfying, because I have no idea why this worked, but I seem to have fixed it.

Server A has two Ethernet ports, an Intel I219V and a Killer E3100. Several months ago, when trying to debug sporadic btrfs errors (I had my RAM installed incorrectly!), I had disabled some unused devices in BIOS, including the Killer Ethernet port.

Since I had no other ideas, and it seemed like this was somehow specific to this server, I just re-enabled the Killer port and switched the Ethernet cable to that port. I'm now getting 300 Mb/s transfers from my wireless devices to my server, exactly as expected.

I'm gonna like... go for a walk or something. Thank you so much to everyone who helped me rule out all of the very many things this could have been! I love this place, you all are so kind and supportive.

Original:

I'm trying to debug a perplexing networking situation, and I could use some guidance if anyone has any.

Here's my setup:

• UniFi Security Gateway
• UniFi Switch Lite
• Two UAPs
• Two servers, A and B, connected to the USW-Lite with GbE
• Many wireless devices, connected to the UAPs

Here's what I'm experiencing:

• Network transfers from the wireless devices to server A (as measured by iperf3 tests) are very slow. Consistently between 10 and 20 Mb/s.
• Network transfers from server A to all devices are expected speeds. 900-1000 Mb/s to server B, 350-ish Mb/s to wireless devices.
• Network transfers between server B and all devices (in both directions!) are expected speeds.
• Network transfers from the USG to server A also seem slow, which is odd. Only about 60 MB/s.
• Network transfers from the USG to server B and the wireless devices is about 300 MB/s

So, specifically network transfers from any wireless device to server A are slow, and no other connections have any issues that I can see.

Some potentially relevant details:

• Server A is running Unraid
• Server B is running Ubuntu
• Wireless devices include a Fedora laptop, an iPhone, and a Macbook Pro
• UniFi configuration is pretty straightforward. I have a few ports forwarded, a guest WiFi network (that none of these devices are on), a single default VLAN, and two simple "Allow LAN" firewall rules for Wireguard on the USG. No other firewall or routing config that I'm aware of.

If anyone has any thoughts at all on how to continue debugging, I would be immensely grateful! I suppose the next step would be to try to determine whether it's the networking equipment or the server itself that is responsible for the throttling, but I'm not sure how best to do that.

I don't intend this to be a sales pitch or anything, I just wanted to share my impression of the Bambu Labs P1P 3D printer in case anyone on here was curious and maybe considering buying one themselves.

I have owned a few Prusa FDM printers over the years but recently tried the Bambu Labs P1P after seeing tons of rave reviews, especially in terms of how fast it prints. Anyone that has done any 3d prints knows that print time is among the least enjoyable aspects of the hobby: lots of waiting.

Right out the gate, the P1P is a solid device with impressive construction given its relatively low price tag (I got it for $600 USD). And this thing easily rivals high performance machines in it's same "category", like the Prusa mk 3 and 4. And those are typically more expensive; the P1P comes 99.5% assembled at that price but a Prusa machine fully assembled is around 60% more expensive.

Most of the "assembly" is just removing packaging, like zip ties, that kept the unit safe and secure during transit. Then you connect the power cable, screen, spool holder, and filament tube. And that's it. The whole thing took maybe 10 minutes.

Getting the WiFi to connect is impossible for me at the moment, but I don't mind copying sliced gcode to the included microsd for printing. Sure, sending the gcode over WiFi would be super cool, but my Prusa doesn't do that so it's not like I've lost something. I'm hoping to eventually figure it out but that's not a deal breaker for me. I'm guessing I just need to temporarily move the printer next to the WiFi router but I haven't made time for it because I'm enjoying just printing off the card.

With the included 0.4mm nozzle (a standard size), it prints typically 2 to 3 times faster. Something that takes 23 hours might take 11. Something that takes 3 hours might take 1. For larger and more complex prints, you can get stuff done so much faster. For smaller and simpler prints, you no longer need to plan batches either first thing in the morning or overnight, you can just start them whenever. Whatever you printed before, you can print 2 to 3 times as many in one go in the same amount of time.

I don't have the AMS system but hope to get that at some point. If it has the same high quality build and performance as the P1P then I'm certain it will bring me simple multi-filament printing. And although I'm not nearly rich enough to afford more than 1 AMS, you can technically connect up to to 4 at once. Each unit holds up to 4 filament spools, so 4x4 means you could theoretically use 16 different filaments in a single print. The colors you could have! But each unit is like $350. Ouch.

I only have 2 real gripes with it so far. First, it purges way too much filament at the start of a print. I get why it does that, it absolutely ensures that your filament is always properly primed to assist in printing that critical first layer correctly, but it feels very wasteful to have a seemingly-excessive amount of filament thrown away with each print.

Second gripe is that the default spool holder is awful to access. You are likely to put the back of the machine facing a wall and that's where the spool holder will end up facing: the wall. You need to ensure the printer is a little more than two spool's width away from the wall - at the very least - so you can slide your spools on and off. Thankfully the bed doesn't move back and forth like with traditional fdm printers, thanks to the corexy technology, so you can more easily plan out where to put it and how much space it will need.

I haven't messed around with them yet but I just got additional hotends for it that I will be testing soon. The pack I got contains 0.2mm for prints that require very fine detail, 0.6mm for prints where detail is slightly less important than speed, and 0.8mm for when you want to go fast and don't care how much detail you get. Because they use a proprietary construction of hotend, you must use theirs, but the upside is that it's fairly fast and simple to switch them out. Most hotends, you just replace the tip, the actual nozzle. But because filament can gunk up the threads, you need to run it hot to unscrew the nozzle, which is very dangerous. With the P1P, you just pull off the magnetic faceplate, undo a few screws, swap the hotend, put the screws back, and pop the faceplate back on. In just a few minutes, you're done. And no need to turn on the hotend either; just unload your filament prior, let it cool down, and swap away. A much safer and more pleasant experience.

Overall, I'm in love with 3d printing all over again. It's the same feeling I got all those years ago when I did my very first 3d print. And sure, the Prusa is still great when you want high quality detailed prints. Going slow and steady wins that particular race still. But I get quality that is 90+% comparable to what the prusa gives me in exchange for literally 2x to 3x print speeds. That's an easy trade for me. And the slicer software estimates that some of my larger and less detailed prints could print in right 2/3 the time using the 0.6mm nozzle instead of the default 0.4mm. That translates to roughly 7 hours on my Prusa (0.4), 3.5 hours in my P1P (0.4), and 2 hours on my P1P (0.6). Given how much easier it is to swap out nozzles on the P1P, I can see myself actually doing that not frequently for certain prints that, like in my example, see substantial benefit.

I'm very excited to see how this machine holds up in the long run!

I have a Xiaomi Redmi 4X device with 2GB RAM and 16GB on-device storage.

Yesterday, I setup PostmarketOS on it, and it works well enough. WiFi and display work well, although no 3D acceleration and no telephony at all. As such, now it is just another device on my home network, except that I can ssh into it to do some basic stuff. Right now it is setup as a Syncthing node to backup my Keepass db and personal knowledge base written in org-mode, but I would like to use it further, and looking for ideas.

Two things to consider, though. First, I don't want it to overcharge and bust the battery. Before when it was on LineageOS, I had a magisk module acc so it would charge only 40-80%, and is largely the reason why the battery holds up pretty well after 5+ years without swelling. I will take further look into it over coming weekend and try to make something like it for the alpine kernel included in PmOS. Second, while on charging the phone keeps vibrating repeatedly. I have no idea how to fix that one, but would like to strat given pointers. (I have never done kernel dev in my life)

So, any ideas on what I can use this extra computer in my metaphorical basement welcome. Thanks in advance.

Saturday Security Brief

Topics: Attack Surface Management, Active iMessage exploit targetting journalists, Academic research on unique EM attack vectors for air-gapped systems.

Any feedback or thoughts on the experience of receiving and discussing news through this brief or in general are welcome. I'm curious about this form of staying informed so I want to experiment. (Thanks again for the suggestion to post the topics as comments.)

Attack Surface Management

This concept is about ensuring that your network is equipped to handle the many issues that arise from accommodating various "Servers, IoT devices, old VPSs, forgotten environments, misconfigured services and unknown exposed assets" with an enterprise environment. Some of the wisdom here can be applied better think about protecting our personal networks as well. Outdated phones, computers, wifi extenders, and more can be a foothold for outside attackers to retain persistant access. Consider taking steps to migigate and avoid potential harm from untamed devices.

Consider putting certain devices on the guest network if your router supports doing so and has extra rules for devices on that network so they can't cause damage to your other devices directly.

"A report from 2016 predicted that 30% of all data breaches by 2020 will be the result of shadow IT resources: systems, devices, software, apps and services that aren’t approved, and in use without the organization’s security team’s knowledge. But shadow IT isn’t the only area where security and IT teams face issues with tracking and visibility."

Attack Surface Management: You Can’t Secure What You Can’t See ~ Security Trails

Multiple Journalists Hacked with ‘Zero-Click’ iMessage Exploit

Mobile spyware is continuing to evolve and tend towards professional solutions. Recently this technology has been abused to conduct espionage on journalists of major networks. Where once these exploits typically required some mistaken click from the user, new developments are allowing their activities without any trace or requiring interaction from the target.

"NSO Group’s Pegasus spyware is a mobile phone surveillance solution that enables customers to remotely exploit and monitor devices. The company is a prolific seller of surveillance technology to governments around the world, and its products have been regularly linked to surveillance abuses."

"In July and August 2020, government operatives used NSO Group’s Pegasus spyware to hack 36 personal phones belonging to journalists, producers, anchors, and executives at Al Jazeera. The personal phone of a journalist at London-based Al Araby TV was also hacked."

"The journalists were hacked by four Pegasus operators, including one operator MONARCHY that we attribute to Saudi Arabia, and one operator SNEAKY KESTREL that we attribute to the United Arab Emirates."

"More recently, NSO Group is shifting towards zero-click exploits and network-based attacks that allow its government clients to break into phones without any interaction from the target, and without leaving any visible traces."

The Great iPwn Journalists Hacked with Suspected NSO Group iMessage ‘Zero-Click’ Exploit ~ Citizen Lab

Security researchers exfiltrate data from air-gapped systems by measuring the vibrations made by PC fans.

Besides this potential exploit the article mentions past research done by Guri and his team which is worth checking out, like:

• LED-it-Go - exfiltrate data from air-gapped systems via an HDD's activity LED

• AirHopper - use the local GPU card to emit electromagnetic signals to a nearby mobile phone, also used to steal data

• MAGNETO & ODINI - steal data from Faraday cage-protected systems

• PowerHammer - steal data from air-gapped systems using power lines

• BRIGHTNESS - steal data from air-gapped systems using screen brightness variations

"Academics from an Israeli university have proven the feasibility of using fans installed inside a computer to create controlled vibrations that can be used to steal data from air-gapped systems."

Academics steal data from air-gapped systems using PC fan vibrations ~ Zdnet

Good Practices

"Hundreds of popular websites now offer some form of multi-factor authentication (MFA), which can help users safeguard access to accounts when their password is breached or stolen. But people who don’t take advantage of these added safeguards may find it far more difficult to regain access when their account gets hacked, because increasingly thieves will enable multi-factor options and tie the account to a device they control. Here’s the story of one such incident."

Turn on MFA Before Crooks Do It For You ~ Krebs on Security

I'm sharing in case some of you are having a similar issue at work or at home, and to hear your opinion and/or similar stories!

I've been using Ubiquiti access points in my home for a few years now, and overall, they've worked very well. 3 APs giving near perfect 5GHz VHT80 coverage on DFS channels. LAN transfers are about 600-650mbit on laptops, which has proven to be plenty for wireless clients in my home. Keep in mind that this is a pretty basic setup... besides the APs, there's just the ISP provided GPON ONT which is also a typical all-in-one ISP solution (router, switch, AP, firewall, DHCP server...) with it's Wi-Fi turned off.

As I said, I was pretty happy with the results, however there was one feature that I could never get to work just right; roaming. You could be walking around the house watching a live stream and the stream would pause for 5-8 seconds until the roaming transition was over. Strangely, with VoIP calls, roaming would be about 3-5 seconds. Even enabling fast roaming features (which I believe is simply 802.11r) on the AP's controller would not give the results I was looking for. After days of tweaking TX power settings, channel selection and trying to implement Minimum RSSI (which I ended up not using), I finally gave up and resigned myself to the 4-6 seconds (oh, the humanity) of roaming time.

Fast forward to about two months ago and I added a new router to the setup (UBNT ER-4) and a switch (UBNT USW-24). Setup went smooth, already had some cat.6 cabling around the house, now it was time to actually use it. Had some fun setting up a guest Wi-Fi network on it's own VLAN, which was always a concern of mine; having "untrusted" devices connect to my network. The access points do client isolation on guest networks by default, but in my mind it wasn't enough as I have some file servers and time machines on the network.

Anyways, a few days after doing the setup I'm walking around the house with a livestream on my mobile and suddenly realize that it's not losing the connection. I try with a VoIP call and it worked flawlessly. I start walking around faster and still, the phone is roaming without an issue. I was very excited!

I'm thinking it must be the router that somehow solved the roaming issue. My first theory was that the DHCP server on the ER-4 was doing it's thing much faster than the ISP's device, allowing the wireless clients to actually roam faster. So I do a web search and I find some very relevant info. It was a thread on a forum and reddit thread with a sysadmin that was about to give up on the APs because of roaming issues. In both threads, there were replies about what switch were they using.

Apparently, some switches (Cisco and HP were mentioned), have a "MAC aging" interval setting which is way too high by default, or they simply have bugged firmware that doesn't allow the switch to "re-learn" the MAC address of a device on a different switch port. I assume that ISP provided "el-cheapo" gear has similar issues.

So, if you're having roaming issues with your wireless clients, check your switches!!!

Anyways, just wanted to share this story. Thank you for reading. :-)

Hi, I need your help to learn pentesting.

I'm programming for several years. I'm really good in C# and can write moderately complex apps in Dart, Python and JavaScript. I'm in highschool and work for software development company as backend developer. But general programming starts to feel so boring...

I've started to watch LiveOverflow on youtube (no link, there is no wifi here and I don't want youtube to drain my data) and it was so interesting - so I tried it. I've tried few CTFs, read many writeups, and now I've discovered CTF hack the box.

When I know what to do, I have no problem googling and researching and later applying my knowledge. But I often discover, that I just don't know what I don't know.

There is one CTF challenge that I haven't completed yet. It's 20 line html page, no javascript, nothing suspicous. No cookies. It has just form with password input, which sends post request to server. Here's the problem - how do I get the flag (the password)? I can bruteforce it, but it clearly isn't the correct way. I know that the php runs on apache, debian. I've tried getting some files, I've tried going up (../), sql injection, nothing works.

And here's the general problem - what am I missing? What to learn? What should I google? I don't want ideas what I'm missing on this one example - Instead I need some sources where I learn generally about vulnerabilities I can exploit. Some blog, some website, something like this.

Could someone here recommend me some sources where I learn about this? How did you start and what things do you generally check when you face something you have to break into?

Thank you

EDIT: Since a few people now have not realized how old this topic is before making a comment, see above date ↑. :)

My old PC's CPU (i7 930) started to critically fail after 8+ years of being overclocked from 2.8 to 4.0 GHz, so I decided to build a new one based on the Ultra-Compact Mini-ITX Gaming PC Build from TechBuyersGuru.

I went with Mini-ITX this time since my old PC was in a huge Antec P193 tower which weighs 16.4kg (36.2lbs) before components and so was a giant PITA to move around. The new Sugo SG13 case is roughly 1/7th the volume and initial weight so is much more convenient to move (but not build!).

p.s. I was unsure whether to post this 'buildapc' style content in ~tech or ~comp.... thoughts?

PCPartPicker Part List
^{Parts labeled incompatible are not... see "Notes" below in Build Process section.}
Salvaged from old PC:
GPU   -     $0 - EVGA - GeForce GTX 980 Ti 6GB Superclocked ACX 2.0+ Video Card
SSD   -     $0 - Samsung - 850 Pro Series 1TB 2.5" Solid State Drive
SSD   -     $0 - Samsung - 840 Pro Series 256GB 2.5" Solid State Drive
HDD   -     $0 - Hitachi - Deskstar NAS 4TB 3.5" 7200RPM Internal Hard Drive

New Components:
Case -   $72 - Silverstone - Sugo SG13B-Q Mini ITX Tower Case
Mobo - $190 - Gigabyte - Z370N WIFI Mini ITX LGA1151 Motherboard
CPU   - $325 - Intel - Core i5-8600K 3.6GHz 6-Core Processor
Cool - $114 - Silverstone - NT06-PRO 74.0 CFM Sleeve Bearing CPU Cooler
RAM   - $220 - Corsair - Vengeance LPX 16GB (2 x 8GB) DDR4-3000 Memory
PSU   - $175 - Silverstone - 600W 80+ Gold Certified Fully-Modular SFX Power Supply
M.2   - $143 - Crucial - MX500 500GB M.2-2280 Solid State Drive
M.2   - $143 - Crucial - MX500 500GB M.2-2280 Solid State Drive

Total:  $1382 (CAD)

Build Process w/ Pictures:

TL;DR - Behold my new Battlestation, IN ALL HER GLORY!!!

After saying goodbye to my old, heavy, oversized, Antec P193 case...
Unboxing the new one, which is almost the same volume as my UPS!...
And prepping all the new PC components for a photo op...
I began the arduous process assembling my new computer.

Everything went fairly smoothly to start. I installed the RAM, M.2 Drives, CPU and CPU Cooler before mounting the motherboard to the case, as instructed in the build guide. The CPU Cooler was a PITA to attach but that's no surprise as they always are.

Note: These "incompatible" parts listed on PCPartsPicker actually do fit together as the build guide said they would. However the RAM and CPU cooler fan are actually touching and I barely managed to squeeze them in together, so the build guide probably isn't lying when it said that particular low-profile RAM might be the only one that actually works with the cooler.

I then mounted the motherboard to the case and began slowly plugging everything else in. This was a particularly slow and frustrating process as I have pretty large hands and everything was incredibly tiny, in incredibly cramped positions, and required more finesse to get in place than I could muster with my fingers alone. As a result I wound up using long needle-nose pliers, including some bent-angle ones, to get most everything plugged in.

This is when I ran into my first major problem though... and one that was not mentioned in the build guide at all. The Case's front panel USB cable wouldn't fit in the motherboard with the CPU cooler fan in place. After trying fruitlessly to get the cable plugged in for 30min I finally gave up and decided to solve the issue the old fashioned way and it plugged in just fine afterwards. (Thanks for saving my ass yet again, Mr. Dremel!)

The other potential issue was due to the CPU cooler and case mounted PSU, which aren't supposed to work together, but once again as the build guide suggested they actually do... with a whopping 3mm clearance between them! At this point I also decided to swap out some of the ribbon power cables that came with the new PSU for some spare braided ones I had from another build since they are much nicer looking and allow for better airflow.

Note: The other supposed incompatibility listed on PCPartPicker is due to the fact that the case only officially supports 3x 2.5" drives or 1x 3.5" with 1x 2.5" but that's easy enough to get around, as explained below.

I also decided to cram an extra SSD under the front case fan, secured with double sided tape to the properly mounted SSD on the case floor panel. It worked just fine and allowed me to get my 3.5" 4TB HDD properly mounted on the underside of the top plate. Linus Tech Tips, in his similar Sugo SG13 build, even managed to squeeze 2 more SSDs above the PSU using double sided tape as well, so I guess that even leaves me with some room to expand my storage later. ;)

The rest of the build assembly process went relatively smoothly and once everything was hooked up, in position and plugged in, it booted straight into windows 10 (which was still on my old 1TB SSD). The moment when a new PC build gets past the POST is always a huge relief, however that momentary relief soon turned to dread as I quickly noticed a pretty big problem; The machine couldn't detect one of my new M.2 SATA drives.

After several hours of frustrated tinkering and much googling I finally found out the reason why, cursing PCPartPicker for not warning me and face-palming pretty hard for not having read the motherboard specs more carefully. It turns out that the Z370N motherboard actually only supports 1x M.2 SATA drive and the second M.2 slot is NVMe only. I had apparently just wasted $140+ on an M.2 SATA drive I couldn't use and my plans to configure them both in RAID 0 was shattered. But that's honestly not the worst part... in order to get the useless M.2 drive back out I had to basically FULLY DISASSEMBLE my entire build again since the NVMe M.2 slot is located on the bottom of the motherboard!

Despite the serious temptation to just leave it in there even though I couldn't use it, I wound up going through with the disassembly purely because I had a pretty good idea for how to actually make use of that second M.2 SATA drive based on something I saw on Linus Tech Tips a few months ago. So rather than leaving it in there or even returning it, after ordering myself the necessary enclosure I now have myself a pretty nice DIY 500GB Thumb drive. ;)

So several hours later after completely taking apart my new build, removing the bottom mounted M.2 SATA drive, and fully reassembling my build once again, I booted it up, it got past the POST and into Windows 10 again. I then reactivated Win 10 on the new hardware configuration (which was surprisingly painless compared to how it used to be where you needed to actually phone Microsoft) and then began the process of installing Linux Mint on the M.2 SATA drive I still had remaining.

Conclusion:
After several days of going at it now, I am finally done and my new computer is fully assembled, functional and ready to use. As always with building computers it was a bit scary, a bit painful, and more than a bit frustrating but ultimately well worth it. I couldn't be happier with the results and can't wait to overclock this bad boy when I get the chance!