Entries Tagged "NSA"

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The NSA on the Risks of Exposing Location Data

The NSA has issued an advisory on the risks of location data.

Mitigations reduce, but do not eliminate, location tracking risks in mobile devices. Most users rely on features disabled by such mitigations, making such safeguards impractical. Users should be aware of these risks and take action based on their specific situation and risk tolerance. When location exposure could be detrimental to a mission, users should prioritize mission risk and apply location tracking mitigations to the greatest extent possible. While the guidance in this document may be useful to a wide range of users, it is intended primarily for NSS/DoD system users.

The document provides a list of mitigation strategies, including turning things off:

If it is critical that location is not revealed for a particular mission, consider the following recommendations:

  • Determine a non-sensitive location where devices with wireless capabilities can be secured prior to the start of any activities. Ensure that the mission site cannot be predicted from this location.
  • Leave all devices with any wireless capabilities (including personal devices) at this non-sensitive location. Turning off the device may not be sufficient if a device has been compromised.
  • For mission transportation, use vehicles without built-in wireless communication capabilities, or turn off the capabilities, if possible.

Of course, turning off your wireless devices is itself a signal that something is going on. It’s hard to be clandestine in our always connected world.

News articles.

Posted on August 6, 2020 at 12:15 PMView Comments

NSA on Securing VPNs

The NSA’s Cybersecurity Directorate — that’s the part that’s supposed to work on defense — has released two documents (a full and an abridged version) on securing virtual private networks. Some of it is basic, but it contains good information.

Maintaining a secure VPN tunnel can be complex and requires regular maintenance. To maintain a secure VPN, network administrators should perform the following tasks on a regular basis:

  • Reduce the VPN gateway attack surface
  • Verify that cryptographic algorithms are Committee on National Security Systems Policy (CNSSP) 15-compliant
  • Avoid using default VPN settings
  • Remove unused or non-compliant cryptography suites
  • Apply vendor-provided updates (i.e. patches) for VPN gateways and clients

Posted on July 15, 2020 at 9:29 AMView Comments

Bart Gellman on Snowden

Bart Gellman’s long-awaited (at least by me) book on Edward Snowden, Dark Mirror: Edward Snowden and the American Surveillance State, will finally be published in a couple of weeks. There is an adapted excerpt in the Atlantic.

It’s an interesting read, mostly about the government surveillance of him and other journalists. He speaks about an NSA program called FIRSTFRUITS that specifically spies on US journalists. (This isn’t news; we learned about this in 2006. But there are lots of new details.)

One paragraph in the excerpt struck me:

Years later Richard Ledgett, who oversaw the NSA’s media-leaks task force and went on to become the agency’s deputy director, told me matter-of-factly to assume that my defenses had been breached. “My take is, whatever you guys had was pretty immediately in the hands of any foreign intelligence service that wanted it,” he said, “whether it was Russians, Chinese, French, the Israelis, the Brits. Between you, Poitras, and Greenwald, pretty sure you guys can’t stand up to a full-fledged nation-state attempt to exploit your IT. To include not just remote stuff, but hands-on, sneak-into-your-house-at-night kind of stuff. That’s my guess.”

I remember thinking the same thing. It was the summer of 2013, and I was visiting Glenn Greenwald in Rio de Janeiro. This was just after Greenwald’s partner was detained in the UK trying to ferry some documents from Laura Poitras in Berlin back to Greenwald. It was an opsec disaster; they would have been much more secure if they’d emailed the encrypted files. In fact, I told them to do that, every single day. I wanted them to send encrypted random junk back and forth constantly, to hide when they were actually sharing real data.

As soon as I saw their house I realized exactly what Ledgett said. I remember standing outside the house, looking into the dense forest for TEMPEST receivers. I didn’t see any, which only told me they were well hidden. I guessed that black-bag teams from various countries had already been all over the house when they were out for dinner, and wondered what would have happened if teams from different countries bumped into each other. I assumed that all the countries Ledgett listed above — plus the US and a few more — had a full take of what Snowden gave the journalists. These journalists against those governments just wasn’t a fair fight.

I’m looking forward to reading Gellman’s book. I’m kind of surprised no one sent me an advance copy.

Posted on May 20, 2020 at 2:08 PMView Comments

Securing Internet Videoconferencing Apps: Zoom and Others

The NSA just published a survey of video conferencing apps. So did Mozilla.

Zoom is on the good list, with some caveats. The company has done a lot of work addressing previous security concerns. It still has a bit to go on end-to-end encryption. Matthew Green looked at this. Zoom does offer end-to-end encryption if 1) everyone is using a Zoom app, and not logging in to the meeting using a webpage, and 2) the meeting is not being recorded in the cloud. That’s pretty good, but the real worry is where the encryption keys are generated and stored. According to Citizen Lab, the company generates them.

The Zoom transport protocol adds Zoom’s own encryption scheme to RTP in an unusual way. By default, all participants’ audio and video in a Zoom meeting appears to be encrypted and decrypted with a single AES-128 key shared amongst the participants. The AES key appears to be generated and distributed to the meeting’s participants by Zoom servers. Zoom’s encryption and decryption use AES in ECB mode, which is well-understood to be a bad idea, because this mode of encryption preserves patterns in the input.

The algorithm part was just fixed:

AES 256-bit GCM encryption: Zoom is upgrading to the AES 256-bit GCM encryption standard, which offers increased protection of your meeting data in transit and resistance against tampering. This provides confidentiality and integrity assurances on your Zoom Meeting, Zoom Video Webinar, and Zoom Phone data. Zoom 5.0, which is slated for release within the week, supports GCM encryption, and this standard will take effect once all accounts are enabled with GCM. System-wide account enablement will take place on May 30.

There is nothing in Zoom’s latest announcement about key management. So: while the company has done a really good job improving the security and privacy of their platform, there seems to be just one step remaining to fully encrypt the sessions.

The other thing I want Zoom to do is to make the security options necessary to prevent Zoombombing to be made available to users of the free version of that platform. Forcing users to pay for security isn’t a viable option right now.

Finally — I use Zoom all the time. I finished my Harvard class using Zoom; it’s the university standard. I am having Inrupt company meetings on Zoom. I am having professional and personal conferences on Zoom. It’s what everyone has, and the features are really good.

Posted on April 30, 2020 at 10:24 AMView Comments

A New Clue for the Kryptos Sculpture

Jim Sanborn, who designed the Kryptos sculpture in a CIA courtyard, has released another clue to the still-unsolved part 4. I think he’s getting tired of waiting.

Did we mention Mr. Sanborn is 74?

Holding on to one of the world’s most enticing secrets can be stressful. Some would-be codebreakers have appeared at his home.

Many felt they had solved the puzzle, and wanted to check with Mr. Sanborn. Sometimes forcefully. Sometimes, in person.

Elonka Dunin, a game developer and consultant who has created a rich page of background information on the sculpture and oversees the best known online community of thousands of Kryptos fans, said that some who contact her (sometimes also at home) are obsessive and appear to have tipped into mental illness. “I am always gentle to them and do my best to listen to them,” she said.

Mr. Sanborn has set up systems to allow people to check their proposed solutions without having to contact him directly. The most recent incarnation is an email-based process with a fee of $50 to submit a potential solution. He receives regular inquiries, so far none of them successful.

The ongoing process is exhausting, he said, adding “It’s not something I thought I would be doing 30 years on.”

Another news article.

EDITED TO ADD (2/13): Another article.

Posted on February 6, 2020 at 6:14 AMView Comments

NSA Security Awareness Posters

From a FOIA request, over a hundred old NSA security awareness posters. Here are the BBC’s favorites. Here are Motherboard’s favorites.

I have a related personal story. Back in 1993, during the first Crypto Wars, I and a handful of other academic cryptographers visited the NSA for some meeting or another. These sorts of security awareness posters were everywhere, but there was one I especially liked — and I asked for a copy. I have no idea who, but someone at the NSA mailed it to me. It’s currently framed and on my wall.

I’ll bet that the NSA didn’t get permission from Jay Ward Productions.

Tell me your favorite in the comments.

Posted on January 31, 2020 at 1:36 PMView Comments

Google Receives Geofence Warrants

Sometimes it’s hard to tell the corporate surveillance operations from the government ones:

Google reportedly has a database called Sensorvault in which it stores location data for millions of devices going back almost a decade.

The article is about geofence warrants, where the police go to companies like Google and ask for information about every device in a particular geographic area at a particular time. In 2013, we learned from Edward Snowden that the NSA does this worldwide. Its program is called CO-TRAVELLER. The NSA claims it stopped doing that in 2014 — probably just stopped doing it in the US — but why should it bother when the government can just get the data from Google.

Both the New York Times and EFF have written about Sensorvault.

Posted on January 28, 2020 at 6:53 AMView Comments

Critical Windows Vulnerability Discovered by NSA

Yesterday’s Microsoft Windows patches included a fix for a critical vulnerability in the system’s crypto library.

A spoofing vulnerability exists in the way Windows CryptoAPI (Crypt32.dll) validates Elliptic Curve Cryptography (ECC) certificates.

An attacker could exploit the vulnerability by using a spoofed code-signing certificate to sign a malicious executable, making it appear the file was from a trusted, legitimate source. The user would have no way of knowing the file was malicious, because the digital signature would appear to be from a trusted provider.

A successful exploit could also allow the attacker to conduct man-in-the-middle attacks and decrypt confidential information on user connections to the affected software.

That’s really bad, and you should all patch your system right now, before you finish reading this blog post.

This is a zero-day vulnerability, meaning that it was not detected in the wild before the patch was released. It was discovered by security researchers. Interestingly, it was discovered by NSA security researchers, and the NSA security advisory gives a lot more information about it than the Microsoft advisory does.

Exploitation of the vulnerability allows attackers to defeat trusted network connections and deliver executable code while appearing as legitimately trusted entities. Examples where validation of trust may be impacted include:

  • HTTPS connections
  • Signed files and emails
  • Signed executable code launched as user-mode processes

The vulnerability places Windows endpoints at risk to a broad range of exploitation vectors. NSA assesses the vulnerability to be severe and that sophisticated cyber actors will understand the underlying flaw very quickly and, if exploited, would render the previously mentioned platforms as fundamentally vulnerable.The consequences of not patching the vulnerability are severe and widespread. Remote exploitation tools will likely be made quickly and widely available.Rapid adoption of the patch is the only known mitigation at this time and should be the primary focus for all network owners.

Early yesterday morning, NSA’s Cybersecurity Directorate head Anne Neuberger hosted a media call where she talked about the vulnerability and — to my shock — took questions from the attendees. According to her, the NSA discovered this vulnerability as part of its security research. (If it found it in some other nation’s cyberweapons stash — my personal favorite theory — she declined to say.) She did not answer when asked how long ago the NSA discovered the vulnerability. She said that this is not the first time the NSA sent Microsoft a vulnerability to fix, but it was the first time it has publicly taken credit for the discovery. The reason is that the NSA is trying to rebuild trust with the security community, and this disclosure is a result of its new initiative to share findings more quickly and more often.

Barring any other information, I would take the NSA at its word here. So, good for it.

And — seriously — patch your systems now: Windows 10 and Windows Server 2016/2019. Assume that this vulnerability has already been weaponized, probably by criminals and certainly by major governments. Even assume that the NSA is using this vulnerability — why wouldn’t it?

Ars Technica article. Wired article. CERT advisory.

EDITED TO ADD: Washington Post article.

EDITED TO ADD (1/16): The attack was demonstrated in less than 24 hours.

Brian Krebs blog post.

Posted on January 15, 2020 at 6:38 AMView Comments

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Sidebar photo of Bruce Schneier by Joe MacInnis.