9 - RHSA-2017:0454

Problem Description:

An update for kvm is now available for Red Hat Enterprise Linux 5.

Red Hat Product Security has rated this update as having a security impact of Important. 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.

2. Relevant releases/architectures:

Red Hat Enterprise Linux Desktop Multi OS (v. 5 client) - x86_64 Red Hat Enterprise Linux Virtualization (v. 5 server) - x86_64

3. Description:

KVM (for Kernel-based Virtual Machine) is a full virtualization solution for Linux on x86 hardware. Using KVM, one can run multiple virtual machines running unmodified Linux or Windows images. Each virtual machine has private virtualized hardware: a network card, disk, graphics adapter, etc.

Security Fix(es):

* Quick emulator (QEMU) built with the Cirrus CLGD 54xx VGA emulator support is vulnerable to an out-of-bounds access issue. It could occur while copying VGA data via bitblt copy in backward mode. A privileged user inside a guest could use this flaw to crash the QEMU process resulting in DoS or potentially execute arbitrary code on the host with privileges of QEMU process on the host. (CVE-2017-2615)

* Quick emulator (QEMU) built with the Cirrus CLGD 54xx VGA Emulator support is vulnerable to an out-of-bounds access issue. The issue could occur while copying VGA data in cirrus_bitblt_cputovideo. A privileged user inside guest could use this flaw to crash the QEMU process OR potentially execute arbitrary code on host with privileges of the QEMU process. (CVE-2017-2620)

Red Hat would like to thank Wjjzhang (Tencent.com Inc.) and Li Qiang (360.cn Inc.) for reporting CVE-2017-2615.

4. 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

Note: The procedure in the Solution section must be performed before this update will take effect.

5. Bugs fixed (https://bugzilla.redhat.com/):

1418200 - CVE-2017-2615 Qemu: display: cirrus: oob access while doing bitblt copy backward mode 1420484 - CVE-2017-2620 Qemu: display: cirrus: potential arbitrary code execution via cirrus_bitblt_cputovideo