Tag Archives: NSA

Military Cryptanalytics, Part III

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2021/01/military-cryptanalytics-part-iii.html

The NSA has just declassified and released a redacted version of Military Cryptanalytics, Part III, by Lambros D. Callimahos, October 1977.

Parts I and II, by Lambros D. Callimahos and William F. Friedman, were released decades ago — I believe repeatedly, in increasingly unredacted form — and published by the late Wayne Griswold Barker’s Agean Park Press. I own them in hardcover.

Like Parts I and II, Part III is primarily concerned with pre-computer ciphers. At this point, the document only has historical interest. If there is any lesson for today, it’s that modern cryptanalysis is possible primarily because people make mistakes

The monograph took a while to become public. The cover page says that the initial FOIA request was made in July 2012: eight and a half years ago.

And there’s more books to come. Page 1 starts off:

This text constitutes the third of six basic texts on the science of cryptanalytics. The first two texts together have covered most of the necessary fundamentals of cryptanalytics; this and the remaining three texts will be devoted to more specialized and more advanced aspects of the science.

Presumably, volumes IV, V, and VI are still hidden inside the classified libraries of the NSA.

And from page ii:

Chapters IV-XI are revisions of seven of my monographs in the NSA Technical Literature Series, viz: Monograph No. 19, “The Cryptanalysis of Ciphertext and Plaintext Autokey Systems”; Monograph No. 20, “The Analysis of Systems Employing Long or Continuous Keys”; Monograph No. 21, “The Analysis of Cylindrical Cipher Devices and Strip Cipher Systems”; Monograph No. 22, “The Analysis of Systems Employing Geared Disk Cryptomechanisms”; Monograph No.23, “Fundamentals of Key Analysis”; Monograph No. 15, “An Introduction to Teleprinter Key Analysis”; and Monograph No. 18, “Ars Conjectandi: The Fundamentals of Cryptodiagnosis.”

This points to a whole series of still-classified monographs whose titles we do not even know.

EDITED TO ADD: I have been informed by a reliable source that Parts 4 through 6 were never completed. There may be fragments and notes, but no finished works.

NSA on Authentication Hacks (Related to SolarWinds Breach)

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2020/12/nsa-on-authentication-hacks-related-to-solarwinds-breach.html

The NSA has published an advisory outlining how “malicious cyber actors” are “are manipulating trust in federated authentication environments to access protected data in the cloud.” This is related to the SolarWinds hack I have previously written about, and represents one of the techniques the SVR is using once it has gained access to target networks.

From the summary:

Malicious cyberactors are abusing trust in federated authentication environments to access protected data. The exploitation occurs after the actors have gained initial access to a victim’s on-premises network. The actors leverage privileged access in the on-premises environment to subvert the mechanisms that the organization uses to grant access to cloud and on-premises resources and/or to compromise administrator credentials with the ability to manage cloud resources. The actors demonstrate two sets of tactics, techniques,and procedures (TTP) for gaining access to the victim network’s cloud resources, often with a particular focus on organizational email.

In the first TTP, the actors compromise on-premises components of a federated SSO infrastructure and steal the credential or private key that is used to sign Security Assertion Markup Language (SAML) tokens(TA0006, T1552, T1552.004). Using the private keys, the actors then forge trusted authentication tokens to access cloud resources. A recent NSA Cybersecurity Advisory warned of actors exploiting a vulnerability in VMware Access and VMware Identity Manager that allowed them to perform this TTP and abuse federated SSO infrastructure.While that example of this TTP may have previously been attributed to nation-state actors, a wealth of actors could be leveraging this TTP for their objectives. This SAML forgery technique has been known and used by cyber actors since at least 2017.

In a variation of the first TTP, if the malicious cyber actors are unable to obtain anon-premises signing key, they would attempt to gain sufficient administrative privileges within the cloud tenant to add a malicious certificate trust relationship for forging SAML tokens.

In the second TTP, the actors leverage a compromised global administrator account to assign credentials to cloud application service principals (identities for cloud applications that allow the applications to be invoked to access other cloud resources). The actors then invoke the application’s credentials for automated access to cloud resources (often email in particular) that would otherwise be difficult for the actors to access or would more easily be noticed as suspicious (T1114, T1114.002).

This is an ongoing story, and I expect to see a lot more about TTP — nice acronym there — in coming weeks.

Related: Tom Bossert has a scathing op-ed on the breach. Jack Goldsmith’s essay is worth reading. So is Nick Weaver’s.

Michael Ellis as NSA General Counsel

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2020/11/michael-ellis-as-nsa-general-counsel.html

Over at Lawfare, Susan Hennessey has an excellent primer on how Trump loyalist Michael Ellis got to be the NSA General Counsel, over the objections of NSA Director Paul Nakasone, and what Biden can and should do about it.

While important details remain unclear, media accounts include numerous indications of irregularity in the process by which Ellis was selected for the job, including interference by the White House. At a minimum, the evidence of possible violations of civil service rules demand immediate investigation by Congress and the inspectors general of the Department of Defense and the NSA.

The moment also poses a test for President-elect Biden’s transition, which must address the delicate balance between remedying improper politicization of the intelligence community, defending career roles against impermissible burrowing, and restoring civil service rules that prohibit both partisan favoritism and retribution. The Biden team needs to set a marker now, to clarify the situation to the public and to enable a new Pentagon general counsel to proceed with credibility and independence in investigating and potentially taking remedial action upon assuming office.

The NSA general counsel is not a Senate-confirmed role. Unlike the general counsels of the CIA, Pentagon and Office of the Director of National Intelligence (ODNI), all of which require confirmation, the NSA’s general counsel is a senior career position whose occupant is formally selected by and reports to the general counsel of the Department of Defense. It’s an odd setup — ­and one that obscures certain realities, like the fact that the NSA general counsel in practice reports to the NSA director. This structure is the source of a perennial legislative fight. Every few years, Congress proposes laws to impose a confirmation requirement as more appropriately befits an essential administration role, and every few years, the executive branch opposes those efforts as dangerously politicizing what should be a nonpolitical job.

While a lack of Senate confirmation reduces some accountability and legislative screening, this career selection process has the benefit of being designed to eliminate political interference and to ensure the most qualified candidate is hired. The system includes a complex set of rules governing a selection board that interviews candidates, certifies qualifications and makes recommendations guided by a set of independent merit-based principles. The Pentagon general counsel has the final call in making a selection. For example, if the panel has ranked a first-choice candidate, the general counsel is empowered to choose one of the others.

Ryan Goodman has a similar article at Just Security.

The NSA is Refusing to Disclose its Policy on Backdooring Commercial Products

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2020/10/the-nsa-is-refusing-to-disclose-its-policy-on-backdooring-commercial-products.html

Senator Ron Wyden asked, and the NSA didn’t answer:

The NSA has long sought agreements with technology companies under which they would build special access for the spy agency into their products, according to disclosures by former NSA contractor Edward Snowden and reporting by Reuters and others.

These so-called back doors enable the NSA and other agencies to scan large amounts of traffic without a warrant. Agency advocates say the practice has eased collection of vital intelligence in other countries, including interception of terrorist communications.

The agency developed new rules for such practices after the Snowden leaks in order to reduce the chances of exposure and compromise, three former intelligence officials told Reuters. But aides to Senator Ron Wyden, a leading Democrat on the Senate Intelligence Committee, say the NSA has stonewalled on providing even the gist of the new guidelines.


The agency declined to say how it had updated its policies on obtaining special access to commercial products. NSA officials said the agency has been rebuilding trust with the private sector through such measures as offering warnings about software flaws.

“At NSA, it’s common practice to constantly assess processes to identify and determine best practices,” said Anne Neuberger, who heads NSA’s year-old Cybersecurity Directorate. “We don’t share specific processes and procedures.”

Three former senior intelligence agency figures told Reuters that the NSA now requires that before a back door is sought, the agency must weigh the potential fallout and arrange for some kind of warning if the back door gets discovered and manipulated by adversaries.

The article goes on to talk about Juniper Networks equipment, which had the NSA-created DUAL_EC PRNG backdoor in its products. That backdoor was taken advantage of by an unnamed foreign adversary.

Juniper Networks got into hot water over Dual EC two years later. At the end of 2015, the maker of internet switches disclosed that it had detected malicious code in some firewall products. Researchers later determined that hackers had turned the firewalls into their own spy tool here by altering Juniper’s version of Dual EC.

Juniper said little about the incident. But the company acknowledged to security researcher Andy Isaacson in 2016 that it had installed Dual EC as part of a “customer requirement,” according to a previously undisclosed contemporaneous message seen by Reuters. Isaacson and other researchers believe that customer was a U.S. government agency, since only the U.S. is known to have insisted on Dual EC elsewhere.

Juniper has never identified the customer, and declined to comment for this story.

Likewise, the company never identified the hackers. But two people familiar with the case told Reuters that investigators concluded the Chinese government was behind it. They declined to detail the evidence they used.

Okay, lots of unsubstantiated claims and innuendo here. And Neuberger is right; the NSA shouldn’t share specific processes and procedures. But as long as this is a democratic country, the NSA has an obligation to disclose its general processes and procedures so we all know what they’re doing in our name. And if it’s still putting surveillance ahead of security.

NSA Advisory on Chinese Government Hacking

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2020/10/nsa-advisory-on-chinese-government-hacking.html

The NSA released an advisory listing the top twenty-five known vulnerabilities currently being exploited by Chinese nation-state attackers.

This advisory provides Common Vulnerabilities and Exposures (CVEs) known to be recently leveraged, or scanned-for, by Chinese state-sponsored cyber actors to enable successful hacking operations against a multitude of victim networks. Most of the vulnerabilities listed below can be exploited to gain initial access to victim networks using products that are directly accessible from the Internet and act as gateways to internal networks. The majority of the products are either for remote access (T1133) or for external web services (T1190), and should be prioritized for immediate patching.

Google Responds to Warrants for “About” Searches

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2020/10/google-responds-to-warrants-for-about-searches.html

One of the things we learned from the Snowden documents is that the NSA conducts “about” searches. That is, searches based on activities and not identifiers. A normal search would be on a name, or IP address, or phone number. An about search would something like “show me anyone that has used this particular name in a communications,” or “show me anyone who was at this particular location within this time frame.” These searches are legal when conducted for the purpose of foreign surveillance, but the worry about using them domestically is that they are unconstitutionally broad. After all, the only way to know who said a particular name is to know what everyone said, and the only way to know who was at a particular location is to know where everyone was. The very nature of these searches requires mass surveillance.

The FBI does not conduct mass surveillance. But many US corporations do, as a normal part of their business model. And the FBI uses that surveillance infrastructure to conduct its own about searches. Here’s an arson case where the FBI asked Google who searched for a particular street address:

Homeland Security special agent Sylvette Reynoso testified that her team began by asking Google to produce a list of public IP addresses used to google the home of the victim in the run-up to the arson. The Chocolate Factory [Google] complied with the warrant, and gave the investigators the list. As Reynoso put it:

On June 15, 2020, the Honorable Ramon E. Reyes, Jr., United States Magistrate Judge for the Eastern District of New York, authorized a search warrant to Google for users who had searched the address of the Residence close in time to the arson.

The records indicated two IPv6 addresses had been used to search for the address three times: one the day before the SUV was set on fire, and the other two about an hour before the attack. The IPv6 addresses were traced to Verizon Wireless, which told the investigators that the addresses were in use by an account belonging to Williams.

Google’s response is that this is rare:

While word of these sort of requests for the identities of people making specific searches will raise the eyebrows of privacy-conscious users, Google told The Register the warrants are a very rare occurrence, and its team fights overly broad or vague requests.

“We vigorously protect the privacy of our users while supporting the important work of law enforcement,” Google’s director of law enforcement and information security Richard Salgado told us. “We require a warrant and push to narrow the scope of these particular demands when overly broad, including by objecting in court when appropriate.

“These data demands represent less than one per cent of total warrants and a small fraction of the overall legal demands for user data that we currently receive.”

Here’s another example of what seems to be about data leading to a false arrest.

According to the lawsuit, police investigating the murder knew months before they arrested Molina that the location data obtained from Google often showed him in two places at once, and that he was not the only person who drove the Honda registered under his name.

Avondale police knew almost two months before they arrested Molina that another man ­ his stepfather ­ sometimes drove Molina’s white Honda. On October 25, 2018, police obtained records showing that Molina’s Honda had been impounded earlier that year after Molina’s stepfather was caught driving the car without a license.

Data obtained by Avondale police from Google did show that a device logged into Molina’s Google account was in the area at the time of Knight’s murder. Yet on a different date, the location data from Google also showed that Molina was at a retirement community in Scottsdale (where his mother worked) while debit card records showed that Molina had made a purchase at a Walmart across town at the exact same time.

Molina’s attorneys argue that this and other instances like it should have made it clear to Avondale police that Google’s account-location data is not always reliable in determining the actual location of a person.

“About” searches might be rare, but that doesn’t make them a good idea. We have knowingly and willingly built the architecture of a police state, just so companies can show us ads. (And it is increasingly apparent that the advertising-supported Internet is heading for a crash.)

The NSA on the Risks of Exposing Location Data

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2020/08/the_nsa_on_the_.html

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.

NSA on Securing VPNs

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2020/07/nsa_on_securing.html

The NSA’s Central Security Service — 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

Bart Gellman on Snowden

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2020/05/bart_gellman_on.html

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 assumed black-bag teams from various countries had 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.

Securing Internet Videoconferencing Apps: Zoom and Others

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2020/04/secure_internet.html

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.

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.

A New Clue for the Kryptos Sculpture

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2020/02/a_new_clue_for_.html

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.

NSA Security Awareness Posters

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2020/01/nsa_security_aw.html

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.

Google Receives Geofence Warrants

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2020/01/google_receives.html

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.

Critical Windows Vulnerability Discovered by NSA

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2020/01/critical_window.html

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.

The NSA Warns of TLS Inspection

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/11/the_nsa_warns_o.html

The NSA has released a security advisory warning of the dangers of TLS inspection:

Transport Layer Security Inspection (TLSI), also known as TLS break and inspect, is a security process that allows enterprises to decrypt traffic, inspect the decrypted content for threats, and then re-encrypt the traffic before it enters or leaves the network. Introducing this capability into an enterprise enhances visibility within boundary security products, but introduces new risks. These risks, while not inconsequential, do have mitigations.


The primary risk involved with TLSI’s embedded CA is the potential abuse of the CA to issue unauthorized certificates trusted by the TLS clients. Abuse of a trusted CA can allow an adversary to sign malicious code to bypass host IDS/IPSs or to deploy malicious services that impersonate legitimate enterprise services to the hosts.


A further risk of introducing TLSI is that an adversary can focus their exploitation efforts on a single device where potential traffic of interest is decrypted, rather than try to exploit each location where the data is stored.Setting a policy to enforce that traffic is decrypted and inspected only as authorized, and ensuring that decrypted traffic is contained in an out-of-band, isolated segment of the network prevents unauthorized access to the decrypted traffic.


To minimize the risks described above, breaking and inspecting TLS traffic should only be conducted once within the enterprise network. Redundant TLSI, wherein a client-server traffic flow is decrypted, inspected, and re-encrypted by one forward proxy and is then forwarded to a second forward proxy for more of the same,should not be performed.Inspecting multiple times can greatly complicate diagnosing network issues with TLS traffic. Also, multi-inspection further obscures certificates when trying to ascertain whether a server should be trusted. In this case, the “outermost” proxy makes the decisions on what server certificates or CAs should be trusted and is the only location where certificate pinning can be performed.Finally, a single TLSI implementation is sufficient for detecting encrypted traffic threats; additional TLSI will have access to the same traffic. If the first TLSI implementation detected a threat, killed the session, and dropped the traffic, then additional TLSI implementations would be rendered useless since they would not even receive the dropped traffic for further inspection. Redundant TLSI increases the risk surface, provides additional opportunities for adversaries to gain unauthorized access to decrypted traffic, and offers no additional benefits.

Nothing surprising or novel. No operational information about who might be implementing these attacks. No classified information revealed.

News article.

Former FBI General Counsel Jim Baker Chooses Encryption Over Backdoors

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/10/former_fbi_gene.html

In an extraordinary essay, the former FBI general counsel Jim Baker makes the case for strong encryption over government-mandated backdoors:

In the face of congressional inaction, and in light of the magnitude of the threat, it is time for governmental authorities­ — including law enforcement­ — to embrace encryption because it is one of the few mechanisms that the United States and its allies can use to more effectively protect themselves from existential cybersecurity threats, particularly from China. This is true even though encryption will impose costs on society, especially victims of other types of crime.


I am unaware of a technical solution that will effectively and simultaneously reconcile all of the societal interests at stake in the encryption debate, such as public safety, cybersecurity and privacy as well as simultaneously fostering innovation and the economic competitiveness of American companies in a global marketplace.


All public safety officials should think of protecting the cybersecurity of the United States as an essential part of their core mission to protect the American people and uphold the Constitution. And they should be doing so even if there will be real and painful costs associated with such a cybersecurity-forward orientation. The stakes are too high and our current cybersecurity situation too grave to adopt a different approach.

Basically, he argues that the security value of strong encryption greatly outweighs the security value of encryption that can be bypassed. He endorses a “defense dominant” strategy for Internet security.

Keep in mind that Baker led the FBI’s legal case against Apple regarding the San Bernardino shooter’s encrypted iPhone. In writing this piece, Baker joins the growing list of former law enforcement and national security senior officials who have come out in favor of strong encryption over backdoors: Michael Hayden, Michael Chertoff, Richard Clarke, Ash Carter, William Lynn, and Mike McConnell.

Edward Snowden also agrees.

EDITED TO ADD: Good commentary from Cory Doctorow.

NSA on the Future of National Cybersecurity

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/10/nsa_on_the_futu.html

Glenn Gerstell, the General Counsel of the NSA, wrote a long and interesting op-ed for the New York Times where he outlined a long list of cyber risks facing the US.

There are four key implications of this revolution that policymakers in the national security sector will need to address:

The first is that the unprecedented scale and pace of technological change will outstrip our ability to effectively adapt to it. Second, we will be in a world of ceaseless and pervasive cyberinsecurity and cyberconflict against nation-states, businesses and individuals. Third, the flood of data about human and machine activity will put such extraordinary economic and political power in the hands of the private sector that it will transform the fundamental relationship, at least in the Western world, between government and the private sector. Finally, and perhaps most ominously, the digital revolution has the potential for a pernicious effect on the very legitimacy and thus stability of our governmental and societal structures.

He then goes on to explain these four implications. It’s all interesting, and it’s the sort of stuff you don’t generally hear from the NSA. He talks about technological changes causing social changes, and the need for people who understand that. (Hooray for public-interest technologists.) He talks about national security infrastructure in private hands, at least in the US. He talks about a massive geopolitical restructuring — a fundamental change in the relationship between private tech corporations and government. He talks about recalibrating the Fourth Amendment (of course).

The essay is more about the problems than the solutions, but there is a bit at the end:

The first imperative is that our national security agencies must quickly accept this forthcoming reality and embrace the need for significant changes to address these challenges. This will have to be done in short order, since the digital revolution’s pace will soon outstrip our ability to deal with it, and it will have to be done at a time when our national security agencies are confronted with complex new geopolitical threats.

Much of what needs to be done is easy to see — developing the requisite new technologies and attracting and retaining the expertise needed for that forthcoming reality. What is difficult is executing the solution to those challenges, most notably including whether our nation has the resources and political will to effect that solution. The roughly $60 billion our nation spends annually on the intelligence community might have to be significantly increased during a time of intense competition over the federal budget. Even if the amount is indeed so increased, spending additional vast sums to meet the challenges in an effective way will be a daunting undertaking. Fortunately, the same digital revolution that presents these novel challenges also sometimes provides the new tools (A.I., for example) to deal with them.

The second imperative is we must adapt to the unavoidable conclusion that the fundamental relationship between government and the private sector will be greatly altered. The national security agencies must have a vital role in reshaping that balance if they are to succeed in their mission to protect our democracy and keep our citizens safe. While there will be good reasons to increase the resources devoted to the intelligence community, other factors will suggest that an increasing portion of the mission should be handled by the private sector. In short, addressing the challenges will not necessarily mean that the national security sector will become massively large, with the associated risks of inefficiency, insufficient coordination and excessively intrusive surveillance and data retention.

A smarter approach would be to recognize that as the capabilities of the private sector increase, the scope of activities of the national security agencies could become significantly more focused, undertaking only those activities in which government either has a recognized advantage or must be the only actor. A greater burden would then be borne by the private sector.

It’s an extraordinary essay, less for its contents and more for the speaker. This is not the sort of thing the NSA publishes. The NSA doesn’t opine on broad technological trends and their social implications. It doesn’t publicly try to predict the future. It doesn’t philosophize for 6000 unclassified words. And, given how hard it would be to get something like this approved for public release, I am left to wonder what the purpose of the essay is. Is the NSA trying to lay the groundwork for some policy initiative ? Some legislation? A budget request? What?

Charlie Warzel has a snarky response. His conclusion about the purpose:

He argues that the piece “is not in the spirit of forecasting doom, but rather to sound an alarm.” Translated: Congress, wake up. Pay attention. We’ve seen the future and it is a sweaty, pulsing cyber night terror. So please give us money (the word “money” doesn’t appear in the text, but the word “resources” appears eight times and “investment” shows up 11 times).

Susan Landau has a more considered response, which is well worth reading. She calls the essay a proposal for a moonshot (which is another way of saying “they want money”). And she has some important pushbacks on the specifics.

I don’t expect the general counsel and I will agree on what the answers to these questions should be. But I strongly concur on the importance of the questions and that the United States does not have time to waste in responding to them. And I thank him for raising these issues in so public a way.

I agree with Landau.

Slashdot thread.