CVE-2017-2620

Quick emulator (QEMU) before 2.8 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.

Weakness

The product reads data past the end, or before the beginning, of the intended buffer.

Affected Software

Name	Vendor	Start Version	End Version
Qemu	Qemu	*	2.8.0 (excluding)
Red Hat Enterprise Linux 5	RedHat	kvm-0:83-277.el5_11	*
Red Hat Enterprise Linux 6	RedHat	qemu-kvm-2:0.12.1.2-2.491.el6_8.7	*
Red Hat Enterprise Linux 7	RedHat	qemu-kvm-10:1.5.3-126.el7_3.5	*
Red Hat Enterprise Linux OpenStack Platform 5.0 (Icehouse) for RHEL 6	RedHat	qemu-kvm-rhev-2:0.12.1.2-2.491.el6_8.7	*
Red Hat Enterprise Linux OpenStack Platform 5.0 (Icehouse) for RHEL 7	RedHat	qemu-kvm-rhev-10:2.6.0-28.el7_3.6	*
Red Hat Enterprise Linux OpenStack Platform 6.0 (Juno) for RHEL 7	RedHat	qemu-kvm-rhev-10:2.6.0-28.el7_3.6	*
Red Hat Enterprise Linux OpenStack Platform 7.0 (Kilo) for RHEL 7	RedHat	qemu-kvm-rhev-10:2.6.0-28.el7_3.6	*
Red Hat OpenStack Platform 10.0 (Newton)	RedHat	qemu-kvm-rhev-10:2.6.0-28.el7_3.6	*
Red Hat OpenStack Platform 8.0 (Liberty)	RedHat	qemu-kvm-rhev-10:2.6.0-28.el7_3.6	*
Red Hat OpenStack Platform 9.0 (Mitaka)	RedHat	qemu-kvm-rhev-10:2.6.0-28.el7_3.6	*
Red Hat Virtualization 4 for Red Hat Enterprise Linux 7	RedHat	qemu-kvm-rhev-10:2.6.0-28.el7_3.6	*
RHEV 3.X Hypervisor and Agents for RHEL-6	RedHat	qemu-kvm-rhev-2:0.12.1.2-2.491.el6_8.7	*
RHEV 3.X Hypervisor and Agents for RHEL-7	RedHat	qemu-kvm-rhev-10:2.6.0-28.el7_3.6	*
Qemu	Ubuntu	trusty	*
Qemu	Ubuntu	upstream	*
Qemu	Ubuntu	xenial	*
Qemu	Ubuntu	yakkety	*
Qemu-kvm	Ubuntu	precise	*
Qemu-kvm	Ubuntu	precise/esm	*
Qemu-kvm	Ubuntu	upstream	*
Xen	Ubuntu	precise	*
Xen	Ubuntu	trusty	*
Xen	Ubuntu	upstream	*

Potential Mitigations

Assume all input is malicious. Use an “accept known good” input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, “boat” may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as “red” or “blue.”
Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code’s environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
To reduce the likelihood of introducing an out-of-bounds read, ensure that you validate and ensure correct calculations for any length argument, buffer size calculation, or offset. Be especially careful of relying on a sentinel (i.e. special character such as NUL) in untrusted inputs.

https://cwe.mitre.org/data/definitions/540.html

NVD	https://nvd.nist.gov/vuln/detail/CVE-2017-2620
CWE	https://cwe.mitre.org/data/definitions/125.html

Out-of-bounds Read

Weakness

Affected Software

Potential Mitigations

References

CVE-2017-2620

Out-of-bounds Read

Weakness

Affected Software

Potential Mitigations

Related Attack Patterns

References