Major security flaw undermines Apple and Google users, researchers discover | Hacker News Reader

Major security flaw undermines Apple and Google users, researchers discover

washingtonpost.com

91 pointsderekjobst23 comments

This news story is way too light on details for this audience. A better description of the vulnerability is here: https://www.freakattack.com/

A summary:

The vulnerability allows attackers to intercept HTTPS connections between vulnerable clients and servers and force them to use ‘export-grade’ cryptogrpahy, which can then be decrypted.

A connection is vulnerable if the server accepts RSA_EXPORT cipher suites and the client either offers an RSA_EXPORT suite or is using a version of OpenSSL that is vulnerable to CVE-2015-0204. Vulnerable clients include many Google and Apple devices (which use unpatched OpenSSL), a large number of embedded systems, and many other software products that use TLS behind the scenes without disabling the vulnerable cryptographic suites.

It also includes a list of vulnerable websites, including sites like mit.edu, groupon.com, marriott.com, and americanexpress.com (!).

Something is odd with that site. If I enter https://www.freakattack.com it reports Safari 5.1.10 as safe from the attack. If I simply enter https://freakattack.com it reports it as vulnerable.

The story has a familiar ring.

Back in the day, Microsoft stored passwords in a fairly insecure format. Then they got security religion, and improved the strength of their password storage dramatically. It was very hard to crack the new format. (I don't remember exactly, but this would have been somewhere around when NT came out.)

But Microsoft was always big on backward compatibility. They wanted users of old machines to still be able to log in to the new servers. So they stored the passwords in the new, strong format, and in the old, weak format, so that they could still authenticate old clients. And that meant that attackers could still get the passwords in the weak format if they could get on the server.

This is from memory, and it's been over a decade, so I may not have all the details exactly correct...

Ah, LM vs NT hash.

http://en.wikipedia.org/wiki/LM_hash

http://en.wikipedia.org/wiki/NT_LAN_Manager#NTLMv1

and

http://en.wikipedia.org/wiki/NT_LAN_Manager#NTLMv2

In summary, the original LM protocol used a "hash" based on 56-bit DES. NTLMv1 supports both the older LM hash and the newer NT hash based on MD4, but still used 56-bit DES encryption to encrypt them (this is what CloudCracker was designed to crack though nothing stops it from using it to crack any DES encryption). NTLMv2 uses HMAC-MD5 instead which fixes the problem.

Yeah, that was it.

I worked on reverse engineering Microsoft's remote desktop protocol (RDP) back in the day. It was wrapped in encryption much like how SSL operates. France outlawed encryption except for authentication, so you just had to put the client and the server in the French country setting and then man in the middle the tcp connection. Reverse engineer away. Thanks France!

Of course, the private key turned out to be hardcoded anyway.

It was more akin to a self signed certificate, but also more complicated depending on domain setup. But also things changed a lot between RDP protocol versions.

It did take me quite a while to reverse engineer the encryption. It was mostly done using IDA Pro and SoftIce. The hardest bit was because I had several crypto books, and whichever Microsoft employee implemented their security kept doing what the books said not to do, so I'd never expect to keep encountering the "wrong" way of doing things.

https://www.hex-rays.com/products/ida/index.shtml

https://en.wikipedia.org/wiki/SoftICE

http://www.rapid7.com/db/vulnerabilities/windows-rdp-constan...

I think the newer RDP versions uses TLS BTW.

I did the reverse engineering on RDP 4, almost 10 years before that vulnerability report. With each RDP release they did very big changes to the security layer as well as other pieces. Somewhat surprisingly Microsoft did base RDP on open standards, especially a whole bunch around video messaging.

But those standards were developed by committee, so the number of ways you could do things was usually the same as the number of committee members. Then their implementation had bugs (eg drawing some parts from bottom to top when the standards said top to bottom), but they didn't know this since they didn't try interoperating with other implementations. The initial "security" was some half assed hack, and yes in later versions they did switch to TLS.

Note that the security is complicated because of domain membership, WAN vs LAN, and a bunch of other related issues.

Ah, is that what the "Disable encryption. This option is only needed (and will only work) if you have a French version of NT TSE." option to rdesktop(1) means. I always wondered about that!

Yep I remember there were password cracker programs that would recover the "LM" version of the password in seconds. I was a network admin at the time and remember having to turn this "feature" off once we discovered it.

If http://dualec.org/DualECTLS.pdf is the actual paper, I am not sure why Apple and Google users are more exposed than others. The paper requires a more thoughtful reading, of couse, but it does not appear to single out these two vendors.

Safari and Android browsers are vulnerable.

http://blog.cryptographyengineering.com/2015/03/attack-of-we...

Firefox for Android seems to be fine? (According to the client test)

I feel puzzled. How can a WP journalist link to three blog posts about the attack, while not linking to the actual researchers' website?

Here it is: https://www.smacktls.com

What is sad is that OpenSSL disabled the EXPORT1024 ciphersuites in 2006. If you don't know what these are, in year 1999 the US government raised the limit to 56-bit encryption and 1024-bit RSA. They were described in https://tools.ietf.org/html/draft-ietf-tls-56-bit-ciphersuit... . And for the record it was in year 2000 that the restrictions was removed for "retail" software.

I love the focus on how the Whitehouse/NSA/FBI sites are vulnerable. Someone could use this to attack the White House!

https://xkcd.com/932/

> Google’s Chrome browser is not vulnerable to the FREAK bug, but the browser that comes built into most Android devices is vulnerable.

Is this true? Both Chrome on my mobile device and on my laptop show as vulnerable on freakattack.com. Both have outstanding updates[1]; however, if only mean the latest version is not vulnerable, I feel like the message that we need to send the layman is "update, now (and really, always)" not "is not vulnerable"

[1] which Chrome wasn't able to actually download earlier, but all seems good now.

If such a suite was enabled, how would the plethora of SSL testing sites out there have graded it? I assume a passing grade would not have allowed insecure suites such as these to be allowed. Insecure cipher is insecure; that would not typically be worthy of a CVE? It sounds more like even if the suite was not on your accepted list, a MITM could cause the server to downgrade?

This is all OpenSSL has to say about it;

  RSA silently downgrades to EXPORT_RSA [Client] (CVE-2015-0204)
  ==============================================================

  Severity: Low

  An OpenSSL client will accept the use of an RSA temporary key in a non-
  export RSA key exchange ciphersuite. A server could present a weak
  temporary key and downgrade the security of the session.

  This issue affects all current OpenSSL versions: 1.0.1, 1.0.0 and 0.9.8.

  OpenSSL 1.0.1 users should upgrade to 1.0.1k.
  OpenSSL 1.0.0 users should upgrade to 1.0.0p.
  OpenSSL 0.9.8 users should upgrade to 0.9.8zd.

  This issue was reported to OpenSSL on 22nd October 2014 by Karthikeyan
  Bhargavan of the PROSECCO team at INRIA. The fix was developed by Stephen
  Henson of the OpenSSL core team.

I find these notes are usually too curt to really understand what's going on...

Also, that CVE is from Jan 8, 2015, while this is claiming to be a new issue disclosed today. I've seen no mention on the oss-security list of "FREAK", so something is borked with this disclosure if it is a new vulnerability...

> In recent days, FBI.gov and Whitehouse.gov have been fixed, though NSA.gov remains vulnerable, said Green.

Haha, the irony. I guess it now proves to NSA why they are also vulnerable when they mandate backdoors in common software.

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