(RHSA-2015:0126) Critical: rhev-hypervisor6 security update

The rhev-hypervisor6 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 extensions.

A heap-based buffer overflow was found in glibc’s
__nss_hostname_digits_dots() function, which is used by the gethostbyname()
and gethostbyname2() glibc function calls. A remote attacker able to make
an application call either of these functions could use this flaw to
execute arbitrary code with the permissions of the user running the
application. (CVE-2015-0235)

A race condition flaw was found in the way the Linux kernel’s KVM subsystem
handled PIT (Programmable Interval Timer) emulation. A guest user who has
access to the PIT I/O ports could use this flaw to crash the host.
(CVE-2014-3611)

A flaw was found in the way OpenSSL handled fragmented handshake packets.
A man-in-the-middle attacker could use this flaw to force a TLS/SSL server
using OpenSSL to use TLS 1.0, even if both the client and the server
supported newer protocol versions. (CVE-2014-3511)

A memory leak flaw was found in the way an OpenSSL handled failed session
ticket integrity checks. A remote attacker could exhaust all available
memory of an SSL/TLS or DTLS server by sending a large number of invalid
session tickets to that server. (CVE-2014-3567)

It was found that the Linux kernel’s KVM subsystem did not handle the VM
exits gracefully for the invept (Invalidate Translations Derived from EPT)
and invvpid (Invalidate Translations Based on VPID) instructions. On hosts
with an Intel processor and invept/invppid VM exit support, an unprivileged
guest user could use these instructions to crash the guest. (CVE-2014-3645,
CVE-2014-3646)

Red Hat would like to thank Qualys for reporting the CVE-2015-0235 issue,
Lars Bull of Google for reporting the CVE-2014-3611 issue, and the Advanced
Threat Research team at Intel Security for reporting the CVE-2014-3645 and
CVE-2014-3646 issues.

Users of the Red Hat Enterprise Virtualization Hypervisor are advised to
upgrade to this updated package.