(Red Hat Issues Fix for Red Hat Enterprise Virtualization) OpenSSL Flaws Let Remote Users Recover DH Keys in Certain Cases and Let Remote Users Negotiate Disabled Ciphers
SecurityTracker Alert ID: 1035242|
SecurityTracker URL: http://securitytracker.com/id/1035242
(Links to External Site)
Date: Mar 10 2016
Disclosure of authentication information, Modification of system information|
Fix Available: Yes Vendor Confirmed: Yes |
Two vulnerabilities were reported in OpenSSL. A remote user can recover keys in certain cases. A remote user can negotiate disabled ciphers. Red Hat Enterprise Virtualization is affected.|
The system may use primes for generating Diffie Hellman (DH) parameters that are not safe when using X9.42 style parameter files [CVE-2016-0701]. A remote user that complete multiple handshakes with the target peer where the peer uses the same private DH exponent may be able to determine the target peer's private DH exponent and then conduct man-in-the-middle attacks against the ostensibly secure connection.
Systems that reuse the private DH exponent or use a static DH ciphersuite are affected.
Systems with the SSL_OP_SINGLE_DH_USE option for ephemeral DH (DHE) in TLS disabled reuse the same private DH exponent for the life of the server process and are affected.
Version 1.0.2 is affected.
The vendor was notified on January 12, 2016
Antonio Sanso (Adobe) reported this vulnerability.
When the SSLv2 protocol is not disabled via SSL_OP_NO_SSLv2 on the target server, a remote user can negotiate SSLv2 ciphers that have been disabled on the target server [CVE-2015-3197]. Versions 1.0.1 and 1.0.2 are affected.
The vendor was notified on December 26, 2015.
Nimrod Aviram and Sebastian Schinzel reported this vulnerability.
A remote user can recover keys in certain cases.|
A remote user can negotiate disabled ciphers.
Red Hat has issued a fix for CVE-2015-3197 for Red Hat Enterprise Virtualization.|
The Red Hat advisory is available at:
Vendor URL: rhn.redhat.com/errata/RHSA-2016-0379.html (Links to External Site)
Access control error, State error|
|Underlying OS: Linux (Red Hat Enterprise)|
|Underlying OS Comments: 6, 7|
This archive entry is a follow-up to the message listed below.|
Source Message Contents
Subject: [RHSA-2016:0379-01] Important: rhev-hypervisor security, bug fix and enhancement update|
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Red Hat Security Advisory
Synopsis: Important: rhev-hypervisor security, bug fix and enhancement update
Advisory ID: RHSA-2016:0379-01
Product: Red Hat Enterprise Virtualization
Advisory URL: https://rhn.redhat.com/errata/RHSA-2016-0379.html
Issue date: 2016-03-09
CVE Names: CVE-2015-3197 CVE-2016-0702 CVE-2016-0705
An updated rhev-hypervisor package that fixes several security issues,
bugs, and enhancements is now available.
Red Hat Product Security has rated this update as having Important
security impact. A Common Vulnerability Scoring System (CVSS) base
score, which gives a detailed severity rating, is available from the
CVE link in the References section.
2. Relevant releases/architectures:
RHEL 7-based RHEV-H - noarch
RHEV Hypervisor for RHEL-6 - noarch
The rhev-hypervisor package provides a Red Hat Enterprise
Virtualization Hypervisor ISO disk image. The Red Hat Enterprise
Virtualization Hypervisor is a dedicated Kernel-based Virtual Machine
(KVM) hypervisor. It includes everything necessary to run and manage
virtual machines: a subset of the Red Hat Enterprise Linux operating
environment and the Red Hat Enterprise Virtualization Agent.
Note: Red Hat Enterprise Virtualization Hypervisor is only available
for the Intel 64 and AMD64 architectures with virtualization
A padding oracle flaw was found in the Secure Sockets Layer version
2.0 (SSLv2) protocol. An attacker could potentially use this flaw to
decrypt RSA-encrypted cipher text from a connection using a newer
SSL/TLS protocol version, allowing them to decrypt such connections.
This cross-protocol attack is publicly referred to as DROWN.
Note: This issue was addressed by disabling the SSLv2 protocol by
default when using the 'SSLv23' connection methods, and removing
support for weak SSLv2 cipher suites. For more information, refer to
the knowledge base article linked in the References section.
A flaw was found in the way malicious SSLv2 clients could negotiate
SSLv2 ciphers that have been disabled on the server. This could
result in weak SSLv2 ciphers being used for SSLv2 connections,
making them vulnerable to man-in-the-middle attacks. (CVE-2015-3197)
A side-channel attack was found that makes use of cache-bank
conflicts on the Intel Sandy-Bridge microarchitecture. An attacker
who has the ability to control code in a thread running on the same
hyper-threaded core as the victim's thread that is performing
decryption, could use this flaw to recover RSA private keys.
A double-free flaw was found in the way OpenSSL parsed certain
malformed DSA (Digital Signature Algorithm) private keys. An
attacker could create specially crafted DSA private keys that, when
processed by an application compiled against OpenSSL, could cause
the application to crash. (CVE-2016-0705)
An integer overflow flaw, leading to a NULL pointer dereference or a
heap-based memory corruption, was found in the way some BIGNUM
functions of OpenSSL were implemented. Applications that use these
functions with large untrusted input could crash or, potentially,
execute arbitrary code. (CVE-2016-0797)
Red Hat would like to thank the OpenSSL project for reporting these
issues. Upstream acknowledges Nimrod Aviram and Sebastian Schinzel
as the original reporters of CVE-2016-0800 and CVE-2015-3197; Yuval
Yarom (University of Adelaide and NICTA), Daniel Genkin (Technion
and Tel Aviv University), Nadia Heninger (University of Pennsylvania)
as the original reporters of CVE-2016-0702; Adam Langley (Google/
BoringSSL) as the original reporter of CVE-2016-0705; and Guido
Vranken as the original reporter of CVE-2016-0797.
All openssl users are advised to upgrade to this updated package,
which contain backported patches to correct these issues. For the
update to take effect, all services linked to the OpenSSL library
must be restarted, or the system rebooted.
Changes to the rhev-hypervisor component:
* Previously, a race between services during boot prevented network
configuration from upgrading correctly. The risk for the race has
now been reduced significantly to allow the upgrade of the network
configuration to complete correctly. (BZ#1194068)
* Previously, using the text user interface (TUI) to log in to the
administrator account of Red Hat Enterprise Virtualization
Hypervisor failed with a Python backtrace. This update makes the
"six" module correctly importable under all circumstances, which
ensures that logging in to Red Hat Enterprise Virtualization
Hypervisor using TUI proceeds as expected. (BZ#1246836)
Before applying this update, make sure all previously released errata
relevant to your system have been applied.
For details on how to apply this update, refer to:
5. Bugs fixed (https://bugzilla.redhat.com/):
1194068 - vdsm-3.5 network conf upgrade fails, due to `service network restart` by node
1236508 - [Tracker] Build RHEV-H for RHEV 3.6.0
1283498 - messages log flooded with 'Failed to reset devices.list on /machine.slice: Invalid argument'
1301846 - CVE-2015-3197 OpenSSL: SSLv2 doesn't block disabled ciphers
1302248 - RHEV-H 7.2 RC1: Remove "Beta" keyword from plymouth
1310593 - CVE-2016-0800 SSL/TLS: Cross-protocol attack on TLS using SSLv2 (DROWN)
1310596 - CVE-2016-0705 OpenSSL: Double-free in DSA code
1310599 - CVE-2016-0702 OpenSSL: Side channel attack on modular exponentiation
1311880 - CVE-2016-0797 OpenSSL: BN_hex2bn/BN_dec2bn NULL pointer deref/heap corruption
6. Package List:
RHEV Hypervisor for RHEL-6:
RHEL 7-based RHEV-H:
These packages are GPG signed by Red Hat for security. Our key and
details on how to verify the signature are available from
The Red Hat security contact is <email@example.com>. More contact
details at https://access.redhat.com/security/team/contact/
Copyright 2016 Red Hat, Inc.
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