Bug 1311893 (CVE-2016-2110)

Summary: CVE-2016-2110 samba: Man-in-the-middle attacks possible with NTLMSSP authentication
Product: [Other] Security Response Reporter: Adam Mariš <amaris>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: aavati, abokovoy, asn, gdeschner, huzaifas, jarrpa, madam, nlevinki, rfortier, rhack, sbose, security-response-team, sgirijan, sisharma, slong, smohan, ssaha, vbellur
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: samba 4.4.1, samba 4.3.7, samba 4.2.10 Doc Type: Bug Fix
Doc Text:
Several flaws were found in Samba's implementation of NTLMSSP authentication. An unauthenticated, man-in-the-middle attacker could use this flaw to clear the encryption and integrity flags of a connection, causing data to be transmitted in plain text. The attacker could also force the client or server into sending data in plain text even if encryption was explicitly requested for that connection.
Story Points: ---
Clone Of: Environment:
Last Closed: 2016-04-19 05:28:19 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: 1322684, 1322686, 1322687, 1322688, 1322689, 1322690, 1322691, 1322692, 1324800, 1324801, 1324802, 1324803, 1324804, 1324805, 1324806, 1324807, 1325382, 1325383, 1325384, 1325385, 1325645, 1325649, 1325650, 1325651, 1325832, 1325838, 1326453    
Bug Blocks: 1311915    

Description Adam Mariš 2016-02-25 09:49:59 UTC
Several flaws were found in Samba's NTLMSSP authentication. An unauthenticated, man-in-the-middle attacker could use this flaw to clear encryption and integrity flags  causing data to be transmitted as plain text, hereby causing a protocol downgrade. The attacker could also mislead the client or server into sending data in plain text, even if encryption explicitly is requested.

LDAP (with NTLMSSP authentication) is used as a client by various administrative Samba-project tools (for example, "net", "samba-tool", "ldbsearch", or "ldbedit"). 

This flaw affects all possible roles in which Samba can operate, and is related to CVE-2016-2112 and CVE-2016-2113.

All uses cases and Samba versions affected.

Comment 9 Huzaifa S. Sidhpurwala 2016-04-11 05:24:37 UTC
Acknowledgements:

Name: the Samba project
Upstream: Stefan Metzmacher (SerNet)

Comment 10 Huzaifa S. Sidhpurwala 2016-04-11 05:44:59 UTC
External Reference:

https://access.redhat.com/articles/2243351

Comment 13 Huzaifa S. Sidhpurwala 2016-04-12 17:09:20 UTC
Public via:

https://www.samba.org/samba/security/CVE-2016-2110.html

Comment 14 Siddharth Sharma 2016-04-12 17:28:10 UTC
Created samba tracking bugs for this issue:

Affects: fedora-all [bug 1326453]

Comment 15 errata-xmlrpc 2016-04-12 17:38:45 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 5

Via RHSA-2016:0613 https://rhn.redhat.com/errata/RHSA-2016-0613.html

Comment 16 errata-xmlrpc 2016-04-12 17:39:48 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 5

Via RHSA-2016:0621 https://rhn.redhat.com/errata/RHSA-2016-0621.html

Comment 17 errata-xmlrpc 2016-04-12 19:16:31 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 5.6 Long Life
  Red Hat Enterprise Linux 5.9 Long Life

Via RHSA-2016:0624 https://rhn.redhat.com/errata/RHSA-2016-0624.html

Comment 18 errata-xmlrpc 2016-04-12 19:17:53 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 5.6 Long Life
  Red Hat Enterprise Linux 5.9 Long Life

Via RHSA-2016:0623 https://rhn.redhat.com/errata/RHSA-2016-0623.html

Comment 19 errata-xmlrpc 2016-04-12 19:33:49 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 6.4 Advanced Update Support
  Red Hat Enterprise Linux 6.2 Advanced Update Support
  Red Hat Enterprise Linux 6.6 Extended Update Support
  Red Hat Enterprise Linux 6.5 Advanced Update Support

Via RHSA-2016:0619 https://rhn.redhat.com/errata/RHSA-2016-0619.html

Comment 20 errata-xmlrpc 2016-04-12 21:21:01 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 4 Extended Lifecycle Support

Via RHSA-2016:0625 https://rhn.redhat.com/errata/RHSA-2016-0625.html

Comment 21 errata-xmlrpc 2016-04-12 21:24:21 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 6.6 Extended Update Support
  Red Hat Enterprise Linux 6.5 Advanced Update Support
  Red Hat Enterprise Linux 6.4 Advanced Update Support
  Red Hat Enterprise Linux 6.2 Advanced Update Support

Via RHSA-2016:0620 https://rhn.redhat.com/errata/RHSA-2016-0620.html

Comment 22 errata-xmlrpc 2016-04-12 21:39:27 UTC
This issue has been addressed in the following products:

  Red Hat Gluster Storage 3.1 for RHEL 7
  Red Hat Gluster Storage 3.1 for RHEL 6

Via RHSA-2016:0614 https://rhn.redhat.com/errata/RHSA-2016-0614.html

Comment 23 errata-xmlrpc 2016-04-13 01:07:06 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7
  Red Hat Enterprise Linux 6

Via RHSA-2016:0612 https://rhn.redhat.com/errata/RHSA-2016-0612.html

Comment 24 errata-xmlrpc 2016-04-13 01:26:39 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7.1 Extended Update Support

Via RHSA-2016:0618 https://rhn.redhat.com/errata/RHSA-2016-0618.html

Comment 25 Fedora Update System 2016-04-13 20:21:11 UTC
samba-4.3.8-0.fc23 has been pushed to the Fedora 23 stable repository. If problems still persist, please make note of it in this bug report.

Comment 26 Fedora Update System 2016-04-14 04:20:55 UTC
samba-4.2.11-0.fc22 has been pushed to the Fedora 22 stable repository. If problems still persist, please make note of it in this bug report.

Comment 27 Fedora Update System 2016-04-15 03:16:42 UTC
samba-4.4.2-1.fc24 has been pushed to the Fedora 24 stable repository. If problems still persist, please make note of it in this bug report.