NSA Cybersecurity Advisory: Patch Remote Desktop Services on Legacy Windows

https://www.nsa.gov/News-Features/News-Stories/Article-View/Article/1865726/nsa-cybersecurity-advisory-patch-remote-desktop-services-on-legacy-versions-of/

by PatrolX • 7 years ago

78 34 7 years ago

nsa.gov

PatrolX3• 7 years ago

The NSA and GCHQ are really concerned about the BlueKeep vulnerability.

It has the potential to do some serious damage.

userbinator2• 7 years ago

In order to increase resilience against this threat while large networks patch and upgrade, there are additional measures that can be taken

I'd say those are the first things that should be done, regardless of the presence of exploits; exposing a port/listening service to the Internet you don't need, especially one that can remotely give complete control to an attacker, is always a bad idea. Fortunately the majority of computers out there are probably behind a NAT, which helps greatly to keep them from being hacked remotely.

Disable remote Desktop Services if they are not required. Disabling unused and unneeded services helps reduce exposure to security vulnerabilities overall and is a best practice even without the BlueKeep threat.

Very good advice --- too bad latest Windows versions have not-so-clearly-described tons of services running by default, many of which phone home in some way, and some of which are nearly impossible to disable...

PatrolX3• 7 years ago

It's pretty amazing that there are over 900k accessible vulnerable endpoints sitting there waiting to be attacked. This is why they're freaking out about it.

Source: https://blog.erratasec.com/2019/05/almost-one-million-vulner...

Eventually someone will wormify that vuln in a few weeks or months and it's going to be a big mess when it happens.

cm21872• 7 years ago

It’s hard to run a windows server remotely without RDP. Most remote administration tools are terrible. Stupid thing like you can’t update windows using remote powershell (which also takes ages to come online after the machine booted).

Rather than disabling RDP which I think is unrealistic, I think a simple way to increase greatly the security is to set up an IP whitelist. Have a list stored on a secure and reliable location (S3 bucket for instance) and a script running every 5 minutes, looking for changes to that list. If it changed run a simple command to update the remote IP restriction to all the administrative services in the windows firewall.

No solution is bullet proof but this allows you to manage the server remotely with very little inconvenience, without requiring to set up a VPN or an internal network, and goes a long way to reduce the exposure to vulnerabilities and brute force attacks.

I would do the same thing with IPMI.

alamortsubite• 7 years ago

I'm not a sysadmin, but it seems even safer and easier to 1) keep Windows behind NAT, 2) ssh port forward through UFW on a cheap Linux box.

crankylinuxuser• 7 years ago

Even nat won't save you. Most NAT assumes unlimited outbound 0.0.0.0/0 tcp/udp/icmp . Almost all configuration is that permissive.

And I just need 1 packet to puncture.

https://samy.pl/pwnat/

userbinator2• 7 years ago

NAT traversal is possible if you happen to be in control of the machines behind the NAT --- that's not very relevant here, since it requires running a special server on the machine you want to exploit (and if you can already do that, i.e. run code on the machine, then there's no point in exploiting RDP...)

The scenario I'm referring to, and the one the article describes, is a remote attacker trying to connect to port 3389 of a machine behind a NAT --- without being able to already access the machine in the first place. In other words: you have a public IP X; there's a machine with private IP Y (which you don't know but may be able to guess easily) behind its NAT. No ports are forwarded. You have no access to the machine. How do you establish a connection to port 3389 (or for that matter, any other listening port) on it?

upofadown• 7 years ago

They probably meant to say that most were behind a firewall. NAT is not any sort of particular protection against anything. Because NAT almost always comes with a firewall there is a tendency to conflate the two things.

Theodores2• 7 years ago

Who has the fear of visiting a URL owned by a three letter agency known for nefarious spying activities?

I do!

So here is a third party report for anyone else that views three letter agency URLs as having all the appeal of a trip to a virtual leper colony:

https://www.zdnet.com/article/even-the-nsa-is-urging-windows...

throwaway2048• 7 years ago

If the NSA was planning to hack you, it wouldn't be via you visiting NSA.gov

idlewords• 7 years ago

I can almost picture the NSA staff meeting: "Let's bait Hacker News randos by issuing an advisory about a nearly internet-wide vulnerability that gives unrestricted access to Windows computers. Then, when they visit our website to learn more, we'll nab them!"

Thanks for taking a bullet for the team on this one, Internet stranger.

PatrolX3• 7 years ago

Reminds me of the UK UFO trap story. In the UK it's illegal to listen to police on scanners so detectives transmitted a hoax radio message about a UFO landing near Doncaster, South Yorkshire, then arrested several people who turned up at the spot, charging them with illegally using scanners to monitor police radio transmissions.

Theodores2• 7 years ago

If this was a story on a paywalled site and I had a non paywall link then I would share it for the benefit of others.

Similarly, if a story is on a website owned by paranoid people with a track record of harm I would prefer to read a third party report. I don't believe I am alone in that.

tedunangst• 7 years ago

Can't trick me into installing your backdoor patch!

diminoten• 7 years ago

You're not important enough to waste a 0day on.

JudgeWapner2• 7 years ago

You can totally trust our advice for all your digital security needs.

- your friendly neighborhood intelligence agency.

gruez• 7 years ago

You don't trust NSA, so you're going to not patch your systems? Are you worried that the patch is a delivery vehicle for their APT implants?

JudgeWapner2• 7 years ago

I'm not worried about anything. Just that an organization whose prime objective it is to hack, exploit, cheat, deceive, and exfiltrate has no place giving advice to the general public.

sitkack• 7 years ago

The fact that NSA does so little for cybersecurity is telling. When they say patch something, it probably means it should be national emergency.

close042• 7 years ago

It means that it’s good to have a backdoor you can use, it’s bad if your enemy can also use it. So the moment NSA pushes you to patch it’s because it’s no longer exclusive to them so the backdoor is no longer an asset but a liability.

beepboopbeep• 7 years ago

Right, so...patch it

tastroder2• 7 years ago

The advisory links to https://www.nsa.gov/Portals/70/documents/what-we-do/cybersec... (PDF)

I really wonder what the utility for that distribution form is, are there people printing these out? Or is there some requirement for them to generate a document ID that they could not get for plain web/HTML documents?

jl6• 7 years ago

Do you mean to ask why is the same content published in PDF format? I quite like PDFs these days. Self-contained, archiveable, readable, sane layout, JavaScript-free, (usually) ad/cookie/tracking-free, no social media sharing buttons... the only drawback is no/poor reflow of text to fit device screen size. But I’ll live with that.

tastroder2• 7 years ago

Kind of, mainly since the PDF looks different enough that it implies manual effort being involved. It felt like an odd choice but I get your points, might just be me then. Thanks.

fbi-director• 7 years ago

Because the NSA has an unknown exploit on Adobe Acrobat PDF Reader, and therefor wants as many downloads of this malicious pdf as possible. From people like us, in positions like us.

/s....?

nocturnial2• 7 years ago

I know we should always assume good faith.

From all the vulnerabilities they know, they chose to publish one that's known and only concerns outdated software. Maybe I'm too skeptical but when the NSA starts leaking fixes for zero day exploits, I'll take them more seriously.

save_ferris• 7 years ago

That’s kinda like saying you’ll only take google seriously when they start releasing their SERP algorithms.

Zero-days are far more useful to them as exploitable points of entry as opposed to patches.

CWuestefeld• 7 years ago

That suggests to me that there's a conflict of interest in the NSA's mission.

Perhaps it's not wise to have the same organization looking after both the defensive aspects of our security, AND also offensive espionage operations.

sigmar• 7 years ago

Why would they leak vulnerabilities they've spent millions of dollars to find? Seems like that would be a waste of money with zero benefit to their mission.

bob_doggo• 7 years ago

I can't exactly say that I trust NSA, and I don't doubt that they have knowledge of vulnerabilities that they aren't releasing.

But I still don't see how that could be a reason to not take this warning seriously.

I think that the cynical view of this would rather be that they consider the potential harm from someone they don't like, making a 1m machines botnet from this, to be greater that the benefit they get from themselves making a 1m machines botnet.

nocturnial2• 7 years ago

Maybe you're right and I'm too cynical, but I see this more like a PR piece to attract talent to their organization.

I think the NSA has a real image problem. They released ghidra. They admitted it was a recruitment tool. They now release this warning which basically tells us to update our software. Anyways, if they really want to improve their image, they need to release zero day exploits and prove it's not just an offensive but also a defensive agency.

The release of an exploitable bug might deny them a couple of targets but will protect millions.

NSA Cybersecurity Advisory: Patch Remote Desktop Services on Legacy Windows

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