oss-sec mailing list archives

Re: Re: CVE Request -- OfflineIMAP -- 1), failed to validate remote SSL server certificate 2), allows SSLv2 protocol


From: Josh Bressers <bressers () redhat com>
Date: Mon, 3 Jan 2011 13:51:11 -0500 (EST)



----- Original Message -----
On Thu, Dec 23, 2010 at 03:43:40PM +0100, Jan Lieskovsky wrote:

  I), Didn't check SSL server certificate

  Description:
  OfflineIMAP prior commit:
  [1]
  https://github.com/nicolas33/offlineimap/commit/4f57b94e2333c37c5a7251fc88dfeda9bc0b226a

  did not perform SSL server certificate validation,
  even when "ssl = yes" option was specified in the
  configuration file. If an attacker was able to get
  a carefully-crafted certificate signed by a
  Certificate Authority trusted by OfflineIMAP,
  the attacker could use the certificate during a
  man-in-the-middle attack and potentially confuse
  OfflineIMAP into accepting it by mistake.

  References:
  [2] http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=603450
  [3] https://bugzilla.redhat.com/show_bug.cgi?id=665382


First of all, thank you very much Jan and all the Redhat team for
reporting it up to the CVE database.

The given patch from Sebastian Spaeth has been released in v6.3.2-rc1.
I
encourage distribution maintainers who want this fix to either

deploy the RC release as is

or

backport the fix against the last release they own.

I expect to release a new stable soon but I still didn't have feedback
from users using SSL. The lack of feedback could mean that

OfflineIMAP users don't expect SSL to work by still refering to the
documentation they know (stating that SSL checks is not supported)

or

they don't hit problems at all.

So, I'll wait a bit more before releasing the next stable.

  II), Allows SSLv2 protocol

  Description:
  In commit:
  [4]
  https://github.com/nicolas33/offlineimap/commit/4f57b94e2333c37c5a7251fc88dfeda9bc0b226a

  when SSL server certificate validation support was added
  to OfflineIMAP it was still possible to use SSL v2 protocol
  version. Version 2 of SSL protocol version is known
  to be prone to multiple deficiencies, each of them
  having security implications (to mention some of them):
  [5] http://en.wikipedia.org/wiki/Secure_Sockets_Layer#Security

  Thus SSLv2 protocol version should be disabled in OfflineIMAP.

  References:
  [6] http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=606962
  [7] https://bugzilla.redhat.com/show_bug.cgi?id=665386

True.

Could you allocate CVE ids for these issues? (though opened for
discussion of any / none of them worthy of it)

As the maintainer of OfflineIMAP, I think both issues should have
their
entry in the CVE List.


As upstream has requested two, here you go:

CVE-2010-4532 offlineimap doesn't check SSL server certificate
CVE-2010-4533 offlineimap allows sslv2

Thanks.

-- 
    JB


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