Bug 659462 (CVE-2010-4180)

Summary: CVE-2010-4180 openssl: NETSCAPE_REUSE_CIPHER_CHANGE_BUG ciphersuite downgrade attack
Product: [Other] Security Response Reporter: Tomas Hoger <thoger>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: djorm, mehmetgelisin, mvadkert, rodney.mckee, tmraz, zzhou
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
URL: http://openssl.org/news/secadv_20101202.txt
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2012-06-18 06:03:56 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 659763, 659764, 659765, 659766, 659771, 659775, 1127896    
Bug Blocks:    

Description Tomas Hoger 2010-12-02 20:41:42 UTC 
Quoting OpenSSL security advisory:

  http://openssl.org/news/secadv_20101202.txt

  A flaw has been found in the OpenSSL SSL/TLS server code where an old bug
  workaround allows malicous clients to modify the stored session cache
  ciphersuite. In some cases the ciphersuite can be downgraded to a weaker one
  on subsequent connections.

Problem affects SSL/TLS server that enable workaround for old Netscape server SSL implementation bug - SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG.  An attacker able to sniff session identifier (sent in plain during the SSL handshake) could use this flaw to force change of the cipher suite in stored session.  Client, that later resumes that session, may start using different (weaker) cipher suite chosen by attacker.

OpenSSL upstream version enable SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG when SSL_OP_ALL option is set (it's common to set this option in applications using OpenSSL).  However, OpenSSL versions in Red Hat Enterprise Linux 5 and 6 have SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG excluded from SSL_OP_ALL (the change was done in response to bug #175779).  Applications can enable Netscape bug workaround on those versions explicitly.

OpenSSL versions prior to 0.9.8j allowed attacker to change stored session cipher quite to arbitrary cipher suite supported by OpenSSL.  Version 0.9.8j corrected this issue to only allow changing cipher suite to those server is configured to use:
  http://cvs.openssl.org/chngview?cn=17489

In both cases, client must accept cipher suite change on resume for the downgrade attack to succeed.

Issue was addressed upstream in 0.9.8q and 1.0.0c by completely disabling this obsolete bug workaround:
  http://cvs.openssl.org/chngview?cn=20131
Comment 5 errata-xmlrpc 2010-12-13 18:15:19 UTC 
This issue has been addressed in following products:

  Red Hat Enterprise Linux 4

Via RHSA-2010:0977 https://rhn.redhat.com/errata/RHSA-2010-0977.html
Comment 6 errata-xmlrpc 2010-12-13 18:35:51 UTC 
This issue has been addressed in following products:

  Red Hat Enterprise Linux 5

Via RHSA-2010:0978 https://rhn.redhat.com/errata/RHSA-2010-0978.html
Comment 7 errata-xmlrpc 2010-12-13 18:41:13 UTC 
This issue has been addressed in following products:

  Red Hat Enterprise Linux 6

Via RHSA-2010:0979 https://rhn.redhat.com/errata/RHSA-2010-0979.html
Comment 10 errata-xmlrpc 2011-06-22 23:16:52 UTC 
This issue has been addressed in following products:

  JBoss Enterprise Web Server 1.0

Via RHSA-2011:0896 https://rhn.redhat.com/errata/RHSA-2011-0896.html