Vulnerability identifier: #VU14116

Vulnerability risk: Low

CVSSv3.1: 6.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2018-12617

CWE-ID: CWE-190

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
QEMU
Client/Desktop applications / Virtualization software

Vendor: QEMU

Description

The vulnerability allows a remote attacker to cause DoS condition on the target system.

The vulnerability exists due to integer overflow in qmp_guest_file_read in qga/commands-posix.c and qga/commands-win32.c in qemu-ga (aka QEMU Guest Agent). A remote attacker can send a specially crafted QMP command (including guest-file-read with a large count value) to the agent via the listening socket, cause a g_malloc0() call to trigger a segmentation fault when trying to allocate a large memory chunk and cause the service to crash.

Mitigation
Install update from vendor's website.

Vulnerable software versions

QEMU: 2.12.50

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External links
http://lists.gnu.org/archive/html/qemu-devel/2018-06/msg03385.html

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.