Vulnerability identifier: #VU21257

Vulnerability risk: Medium

CVSSv3.1: 6.6 [CVSS:3.1/AV:A/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-14835

CWE-ID: CWE-119

Exploitation vector: Local network

Exploit availability: No

Vulnerable software:
Linux kernel
Operating systems & Components / Operating system

Vendor: Linux Foundation

Description

The vulnerability allows a remote attacker to escalate privileges on the system.

The vulnerability exists due to a boundary error within the vhost/vhost_net Linux kernel module during the live migration flow when processing dirty log entries. A privileged guest user can pass descriptors with invalid length to the host when migration is on the way, trigger buffer overflow and execute arbitrary code on the host OS.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Linux kernel: 5.2.1 - 5.2.17, 5.1.1 - 5.1.21, 5.0.0 - 5.0.21, 4.9.1 - 4.9.194, 4.8.0 - 4.8.17, 4.7.0 - 4.7.10, 4.6.0 - 4.6.7, 4.5.0 - 4.5.7, 4.4.0 - 4.4.194, 4.3.1 - 4.3.6, 4.2.0 - 4.2.8, 4.1.1 - 4.1.52, 4.0.0 - 4.0.9, 3.9.0 - 3.9.11, 3.8.0 - 3.8.13, 3.7.1 - 3.7.10, 3.6.1 - 3.6.11, 3.5.1 - 3.5.7, 3.4.1 - 3.4.113, 3.3.1 - 3.3.8, 3.2.1 - 3.2.93, 3.1.1 - 3.1.10, 3.0.1 - 3.0.101, 2.6.34 - 2.6.39.4

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External links
http://www.openwall.com/lists/oss-security/2019/09/17/1
http://github.com/torvalds/linux/commit/060423bfdee3f8bc6e2c1bac97de24d5415e2bc4
http://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git/commit/?h=for_linus&id=060423b...

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated privileged user via the local network (LAN).

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.