OpenSSL: Denial of Service -- Existing Account

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             AUSCERT External Security Bulletin Redistribution

                               ESB-2017.2348
   CVE-2017-14033: Buffer underrun vulnerability in OpenSSL ASN1 decode
                             15 September 2017

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        AusCERT Security Bulletin Summary
        ---------------------------------

Product:           OpenSSL
Publisher:         Ruby
Operating System:  Windows
                   UNIX variants (UNIX, Linux, OSX)
Impact/Access:     Denial of Service -- Existing Account
Resolution:        Patch/Upgrade
CVE Names:         CVE-2017-14033  

Original Bulletin: 
   https://www.ruby-lang.org/en/news/2017/09/14/openssl-asn1-buffer-underrun-cve-2017-14033/

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CVE-2017-14033: Buffer underrun vulnerability in OpenSSL ASN1 decode

Posted by usa on 14 Sep 2017

There is a buffer underrun vulnerability in OpenSSL bundled by Ruby. This 
vulnerability has been assigned the CVE identifier CVE-2017-14033.

Details

If a malicious string is passed to the decode method of OpenSSL::ASN1, buffer
underrun may be caused and the Ruby interpreter may crash.

All users running an affected release should either upgrade or use one of the
workarounds immediately.

Affected Versions

Ruby 2.2 series: 2.2.7 and earlier

Ruby 2.3 series: 2.3.4 and earlier

Ruby 2.4 series: 2.4.1 and earlier

prior to trunk revision 56946

Workaround

The OpenSSL library is also distributed as a gem. If you cant upgrade Ruby 
itself, install OpenSSL gem newer than version 2.0.0. But this workaround is 
only available with Ruby 2.4 series. When using Ruby 2.2 series or 2.3 series,
the gem does not override the bundled version of OpenSSL.

Credit

Thanks to asac for reporting this issue.

History

Originally published at 2017-09-14 12:00:00 (UTC)

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