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Tenda firmware (multiple versions) contains hidden authentication backdoor

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Re: Tenda firmware (multiple versions) contains hidden authentication backdoor

#71
this is definitely a backdoor, not necessarily that they use it to infiltrate users but definitely they put them at risk.

reminds me of a bug I found in some tplink router it compared passwords of 3 different users but that table was empty so basically 15 NULL bytes would log you in as admin lol

Re: Tenda firmware (multiple versions) contains hidden authentication backdoor

#72

> The associated username is not validated, so any provided username will succeed when paired with the backdoor password. Great. I am really wondering why should the customers trust these manufacturers. At this point I would not use any router with vendor-provided black box firmware. Full stop. I would always install OpenWRT or something similar on it before using it. And if that is not possible for whatever reason,…

good approach, but your security should not depend on your router anyway, you should be immune to attacks from it

Not exposing your management interface to internet and running a guest network which doesn't have access to said management interfaces can block 95%+ of the attacks, I believe.

Re: Tenda firmware (multiple versions) contains hidden authentication backdoor

#73

Earlier quoted context omitted.

good approach, but your security should not depend on your router anyway, you should be immune to attacks from it

Not exposing your management interface to internet and running a guest network which doesn't have access to said management interfaces can block 95%+ of the attacks, I believe.

yes, defense in depth

Re: Tenda firmware (multiple versions) contains hidden authentication backdoor

#74
post #43
post #39

Earlier quoted context omitted.

In computer security, never attribute to ignorance that which is adequately explained by malice.

You’ve got the saying backwards: “Never attribute to malice that which is adequately explained by stupidity.” https://en.wikipedia.org/wiki/Hanlon%27s_razor

Looks like this time you interpreted the message in a malicious way.

Re: Tenda firmware (multiple versions) contains hidden authentication backdoor

#75

> The associated username is not validated, so any provided username will succeed when paired with the backdoor password. Great. I am really wondering why should the customers trust these manufacturers. At this point I would not use any router with vendor-provided black box firmware. Full stop. I would always install OpenWRT or something similar on it before using it. And if that is not possible for whatever reason,…

Hm, do you ever go over 1gbit? If my understanding is correct, good affordable routers like Mikrotik's CCR2004 are fully closed, so the only option is to build your own shitty box which will be much less energy efficient than their specialized switch chips.

Re: Tenda firmware (multiple versions) contains hidden authentication backdoor

#76
post #49

Earlier quoted context omitted.

Yes, I got their point. My point is that’s the opposite of reality.

His point is that in security, the opposite applies. The supposed "incompetence" is just plausible deniability for a malicious act.

Yes, and my point is that hasn’t been the case in my experience.

Re: Tenda firmware (multiple versions) contains hidden authentication backdoor

#77
post #49

Earlier quoted context omitted.

Yes, I got their point. My point is that’s the opposite of reality.

Maybe it's time to take a closer look at reality and correct this meme, which might casually blur the issue and deflect responsibility? Looking at the IT security landscape we see every layer, every product category if not every product itself riddled with issues at one point or another. At the same time the incentives to put those security issues in are huge, and we know attackers work systematic, creative and persi…

> I wouldn't assume that all of those security mishaps stem from an endless series of blunders from "stupid" programmers.

The saying doesn’t mean that all vulnerabilities are blunders. It means we shouldn’t automatically assume vulnerabilities are nefarious.

If closer inspection proves beyond reasonable doubt that it was placed there deliberately and maliciously then that’s different.

But the point is most vulnerabilities are blunders so it’s better to assume that until proven otherwise.

Re: Tenda firmware (multiple versions) contains hidden authentication backdoor

#78
post #43

Earlier quoted context omitted.

You’ve got the saying backwards: “Never attribute to malice that which is adequately explained by stupidity.” https://en.wikipedia.org/wiki/Hanlon%27s_razor

Looks like this time you interpreted the message in a malicious way.

How? Neither their comment nor mine have anything malicious in their tone nor content.

Re: Tenda firmware (multiple versions) contains hidden authentication backdoor

#79

> The associated username is not validated, so any provided username will succeed when paired with the backdoor password. Great. I am really wondering why should the customers trust these manufacturers. At this point I would not use any router with vendor-provided black box firmware. Full stop. I would always install OpenWRT or something similar on it before using it. And if that is not possible for whatever reason,…

Last time when I looked OpenWRT was unable to support MIMO and beamforming capabilities of many of the devices it was running on. This capabilities are crucial to have decent coverage, signal strength and throughput where I live (i.e.: crowded/congested wireless networks in an apartment complex). Did OpenWRT team managed to work around them, or did the manufacturers started to play nicer with open drivers with loadab…

Some routers specifically allow openWRT.. example, Routers like the GL.iNet GL-MT6000 (Flint 2) and TP-Link Archer AX6000 come with OpenWrt pre-installed and are designed for easy OpenWrt use.

Re: Tenda firmware (multiple versions) contains hidden authentication backdoor

#80
Oh this is amazing! I have a few of their cube routers sitting around and I always hated how app-locked their firmware was when it really is just a wifi repeater with a few extras (mesh) on top. Root access will do wonders to bypassing the app now (and also disabling their ping-for-green-light mechanism which spams the network with a constant dns resolution to microsoft.com lol).

Also honest take this looks less like a "backdoor" (implies malicious - this is a link to a CVE after all) and more like a developer access credential/default credential that was burned into the firmware (i'd imagine the code remains but on a production run they randomize the key so its non-guessable but then you get lazy and dont run that extra step and this slips in/you burn the bare firmware with no production configs).

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