167

Short answer: do a factory reset, update the firmware, and you are good to go. The risk is very low, bordering zero. The previous owner may have installed a custom firmware or changed its configuration, but a firmware upgrade and factory reset is enough to take care of almost every change. The risk that the previous owner tampered with the router and his ...


86

No. You should not rely upon the obscurity of your firmware in order to hide potential security vulnerabilities that exist regardless of whether or not you encrypt/obfuscate your firmware. I have a radical suggestion: do the exact opposite. Make your firmware binaries publicly available and downloadable, freely accessible to anyone who wants them. Add a ...


56

Sure - it could be a signed image. If the router has a built-in public key, and the image was signed by the corresponding private key, it would be perfectly safe. Unless someone had got the private key, and uploaded a malicious version to the server, in which case, HTTPS wouldn't help either.


41

Historically, the open source movement is not about security but about freedom. Basically, Richard Stallman was very dismayed at not being able to fiddle with his printer because the driver source was unavailable. OpenBSD's stance on being "secure" does not come from it being open source, but on an avowed goal and pledge to do things properly with regards ...


31

You could use a tool like Wireshark to analyze your outbound traffic (you need to be upstream of the device) and look for unexpected/suspicious outbound traffic. Of course, it could be infrequent or only triggered by certain activities, so you'd need a large volume of data to analyze. And you'd need to be able to analyze (at least traffic analysis) the ...


25

Open Source Does Not Unequivocally = More Secure/Safe Anyone CAN look at open source software/hardware, but that doesn't guarantee that "anyone" WILL look at it; further, if they do look at it, it also doesn't mean that they will disclose something that they find that could be a vulnerability. People assume too much about open source, and one of the ...


23

It is probably safe. But downloading over https should be preferred if possible. Without https: If there is a flaw in the signature mechanism, it can be exploited (example: https://github.com/QubesOS/qubes-issues/issues/2520 ) An attacker can know which firmware/version you install (so if there is known flaws in that firmware/version , it could be ...


23

The main risk is that the firmware has been replaced by a malicious version, which could make it possible to intercept all the traffic on your network. Passwords, injecting malware, redirecting you to malicious sites, etc. That's a worst-case scenario but easy for someone to do. You want to factory reset the device to try to clear out anything that the ...


20

Leaving aside the "open source == secure" argument, you can also look at this question as "Why run a secure OS when the BIOS/firmware isn't guaranteed to be secure". Why bother locking my front door when an attacker can just break the windows? You will never make a completely secure system. What you can do is make sure you work on securing the parts that ...


18

By far, your main risk in buying an "open box" router is that the router has some subtle damage that the manufacturer didn't detect but that will ultimately reduce the lifespan of the device. That's one reason why they often have reduced warranties. Security-wise, the risk is negligible if you do a factory reset and re-flash the firmware. That should re-...


16

PPTP is thoroughly broken. At this point nobody who cares in the least about the communications they intend to protect should be using it. And it's not a matter of choosing someone's implementation over another; its most serious flaws are in the protocol design and cannot be fixed. MSCHAPv1 was broken 15 years ago, as you noted in your question. Its ...


13

Firmware configuration Writing to the BIOS is a privileged operation, only doable by the superuser. Many BIOSes attempt to prevent this, for example by locking the SPI write bit and limiting the ability of SMM to interact with the BIOS. Unfortunately, there are so many ways to modify the BIOS that many (most?) firmware vendors do not adequately lock down ...


12

A USB device with "manipulated firmware" can sure do evil things. For an extreme case, see this answer: the USB device may tell to the OS "hey, I am the FireWire-to-USB converter X.Y, please download my driver from your vendor, then grant me full DMA access when I say so". Though theoretical yet, this is not science-fiction, and it sure is scary. For more ...


11

Most manufacturer's firmwares for routers are actually built around the same open source software as open source alternative like dd-wrt. The real security distinction is not between a "manufacturer" and an "open source" firmwares; it is between a maintained firmware against one that is not. A crucial element for security is how promptly fixes for discovered ...


11

Doubtful it would be beneficial. It is by far a better option to push it open-source than closed source. It might seem silly and even controversial at first, but opening up a project to the public has plenty of benefits. While there are people with malicious intents, there are also people wanting to help and make the internet a better place. Open source ...


10

Quis custodiet ipsos custodes? Before I begin, I'd like to explain a bit about the term trust as it is used in an information security context. In infosec, trust often has the opposite meaning of what would seem logical. You want less trust. An untrusted component of a system is good, and the more untrusted components, the better. Trust means reliance. If ...


10

AMT is is hardly a secret. It is a feature for IT departments to get pseudo-console access to PCs over the network and remotely manage them. (The common term is Out of Band or OOB management.) It is comparable to HP’s iLO or Dell’s iDRAC, which are for servers. In the case of servers, there is usually a dedicated NIC for OOB. For desktops, that is not ...


9

Nothing. If you cannot trust your hardware, you cannot trust it. There does not exist a universal way of updating keyboard controllers, and certainly there is no universal introspection for them. While you could reflash those keyboards that are reflashable every time the system boots or a keyboard is plugged in, you'd have to come up with a way to do this ...


8

You have quite a few different questions in here. Let's try to answer them. Are DVD drives & SATA infrastructure vulnerable like badusb The SATA protocol is used exclusively for storage, not any other class like a keyboard. "BadUSB" is a class of frankly overhyped attacks that involve a USB devices acting as a Human Interface Device (HID) like a ...


8

In short: If you really care about stuff like that, go into a retail store and buy a new router that's on stock. The risk is small, but you can't easily mitigate it. I could imagine some creep buying lots of routers, returning them and then spying on the people who bought them just for the kick of it. Or of course some evil organization. This risk is small, ...


7

BIOS Most memory chips I've worked with have a W or R/W pin which selects the write mode. Physically tying that one to appropriate logical level should do the trick. Write-protected USB drives I'm a bit suspicious about this one. I've implemented microcontroller<->SD card interface, and the "write-protect" bit is handled completely in software, so you ...


7

There is a standard to write firmware, the ATA DOWNLOAD_MICROCODE command and the segmented version (transfer protocol 3), but there is no standard for reading the firmware back. As another answer says, some manufacturers may add their own vendor-specific techniques to do so. There is another reliable way to access firmware, but it cannot be done from ...


7

What are the main risks in this scenario? I know this is not the intent of your question, but in my opinion the main risk is not to you, but to the previous owner. Chances are that the credentials of the previous owner are still present on the device. You may gain access to the account of the previous owner this way. Resold devices are often not cleared at ...


6

Firmware is code. It executes on the CPU on behalf of some hardware device; or it executes on the device directly. In general, if your own hardware is intent on spying on you, then you lose. A more worrying development is that many pieces of hardware (e.g. keyboards) contain a completely honest firmware that is upgradeable, and some malware has been spotted ...


6

There's a chicken-and-egg problem with the "firewall" solution: your keyboard and mouse are USB devices*. How do you as the user tell the OS that you want to give permission to the keyboard and mouse, without using either of them? What about if the keyboard and mouse are connected through USB ports on a monitor -- they'll be disconnected and reconnected ...


6

Open source (free/libre) software is not (primarily) about security. One of its more important aspects is trust: you can verify what's running, it is much harder to hide something malicious. Some people also claim to more people will (might) be reading the code, which means chances are higher of vulnerabilities being found and fixed, resulting in higher code ...


6

what this allows an attacker to do? It allows an attacker to execute arbitrary code in System Management Mode (SMM), a highly privileged execution mode of x86 processors. This mode is transparent to the Operating System (OS) and it is more privileged than any other mode. If an attacker can execute code in SMM, it basically owns the platform/computer (more ...


6

Why doesn't Google distribute Android firmware images with lots of included drivers, ... This means that Google would need to get access to the drivers in the first place and not only by binary but also by source. Only this way they could keep the drivers working when major changes to the software are made: new versions of Android usually use newer versions ...


6

Probably there's a digital signature on the firmware and a key on the router. If the update file is tampered somehow, the signature verification will fail and the router will reject the update. It works, but employing SSL would be better.


6

A well-designed firmware should rely on the strength of its access key rather than relying on the attacker's ignorance of the system design. This follows the foundational security engineering principle known as Kerckhoffs's axiom: An information system should be secure even if everything about the system, except the system's key, is public knowledge. ...


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