RHSA-2016:1607 - Security Advisory

Topic

An update for qemu-kvm-rhev is now available for RHEV-H and Agents for RHEL-7.

Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

KVM (Kernel-based Virtual Machine) is a full virtualization solution for Linux on AMD64 and Intel 64 systems. The qemu-kvm-rhev package provides the user-space component for running virtual machines using KVM in environments managed by Red Hat Enterprise Virtualization Manager.

Security Fix(es):

• Quick Emulator(Qemu) built with the Block driver for iSCSI images support (virtio-blk) is vulnerable to a heap buffer overflow issue. It could occur while processing iSCSI asynchronous I/O ioctl(2) calls. A user inside guest could use this flaw to crash the Qemu process resulting in DoS or potentially leverage it to execute arbitrary code with privileges of the Qemu process on the host. (CVE-2016-5126)
• Quick emulator(Qemu) built with the virtio framework is vulnerable to an unbounded memory allocation issue. It was found that a malicious guest user could submit more requests than the virtqueue size permits. Processing a request allocates a VirtQueueElement and therefore causes unbounded memory allocation on the host controlled by the guest. (CVE-2016-5403)

Red Hat would like to thank hongzhenhao (Marvel Team) for reporting CVE-2016-5403.

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

After installing this update, shut down all running virtual machines. Once all virtual machines have shut down, start them again for this update to take effect.

Affected Products

• Red Hat Virtualization 3 for RHEL 7 x86_64
• Red Hat Virtualization for IBM Power LE 3 ppc64le

Fixes

• BZ - 1340924 - CVE-2016-5126 Qemu: block: iscsi: buffer overflow in iscsi_aio_ioctl
• BZ - 1358359 - CVE-2016-5403 Qemu: virtio: unbounded memory allocation on host via guest leading to DoS

CVEs

• CVE-2016-5126
• CVE-2016-5403

References

• https://access.redhat.com/security/updates/classification/#moderate