Issue #9424 has been updated by B Kelly.


 shyouhei / ruby-lang.org wrote:
 > 
 > We are amateur about security.  It might be possible to change
 > something, then we have no idea what happens with that modification
 > and even worse, we cannot maintain that bit when security research
 > develops and turned out our change was in fact ill.
 
 I am also an amateur.  But I read the logic of your statement above as
 being in favor of discarding security research that /already exists/
 about the weak ciphers and protocol versions.
 
 But: if we are to disregard current research, should not the reason given
 be something other than concern over possible future research?
 
 
 With regard to maintenance, could it be useful to incorporate a check
 like https://gist.github.com/cscotta/8302049 in the form of an automated
 test which can be run by maintainers prior to the release of a new version
 of ruby?  The idea being that such a test may assist in proactively warning
 maintainers if/when further improvements to ruby's OpenSSL defaults are
 warranted.
 
 
 
 Regards,
 
 Bill

----------------------------------------
Bug #9424: ruby 1.9 & 2.x has insecure SSL/TLS client defaults 
https://bugs.ruby-lang.org/issues/9424#change-44500

* Author: Jeff Hodges
* Status: Assigned
* Priority: Normal
* Assignee: Martin Bosslet
* Category: ext/openssl
* Target version: current: 2.2.0
* ruby -v: ruby 2.1.0p0 (2013-12-25 revision 44422) [x86_64-darwin12]
* Backport: 1.9.3: UNKNOWN, 2.0.0: UNKNOWN, 2.1: UNKNOWN
----------------------------------------
Ruby 1.9, 2.0, and 2.1 use insecure defaults for SSL/TLS client connections. They have inherited or overridden configs that make the OpenSSL-controlled connections insecure. Note: both OpenSSL's and Ruby's defaults in all tested versions are currently insecure. Confirmation of the issues with Ruby's TLS client can be done with the code in [1].

Ruby is using TLS compression by default. This opens Ruby clients to the CRIME attack[2].

Ruby also uses a variety of insecure cipher suites. These cipher suites either use key sizes much smaller than the currently recommended size, making brute forcing a decryption easy, or do not check the veracity of the server's certificate making them susceptible to man-in-the-middle attacks[3][4].

Ruby also appears to allow SSLv2 connections by default. It does so by first trying to connect with a SSLv2 client hello with a higher SSL/TLS version inside of it which allows SSLv2 servers to work. SSLv2 was broken in the 1990s and is considered unsafe.

These issues expose Ruby users to attacks that have been known for many years, and are trivial to discover. These defaults are often build specific, and are not the same across platforms, but are consistently poor (the code in [1] can evaluate the build). A patch from a core developer on the security@ list is attached. However, the patch does not correct the suspect SSLv2 configuration. It is believed that Ruby 1.8 is also a concern, but, since it was obsoleted, it's not been investigated.

A report similar to this was sent to security / ruby-lang.org four days ago. The Ruby core developers have been unable to patch these problems in a timely manner for it for what I and others believe are concerning reasons. This ticket is being made to allow engineers outside of the small group that are on security@ to protect themselves from these attacks.

[1] https://gist.github.com/cscotta/8302049
[2] https://www.howsmyssl.com/s/about.html#tls-compression
[3] https://www.howsmyssl.com/s/about.html#insecure-cipher-suites
[4] TLS_DHE_DSS_WITH_DES_CBC_SHA - small keys
TLS_DHE_RSA_WITH_DES_CBC_SHA - small keys
TLS_ECDH_anon_WITH_3DES_EDE_CBC_SHA - MITM
TLS_ECDH_anon_WITH_AES_128_CBC_SHA - MITM
TLS_ECDH_anon_WITH_AES_256_CBC_SHA - MITM
TLS_ECDH_anon_WITH_RC4_128_SHA - MITM
TLS_RSA_WITH_DES_CBC_SHA - small keys
TLS_SRP_SHA_WITH_3DES_EDE_CBC_SHA - MITM
TLS_SRP_SHA_WITH_AES_128_CBC_SHA - MITM
TLS_SRP_SHA_WITH_AES_256_CBC_SHA - MITM

---Files--------------------------------
ruby_ssl.patch (1.08 KB)


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