Debian DSA-4667-1 : linux - security update

Medium Nessus Plugin ID 136124

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VPR Score: 6.7

Synopsis

The remote Debian host is missing a security-related update.

Description

Several vulnerabilities have been discovered in the Linux kernel that may lead to a privilege escalation, denial of service, or information leak.

- CVE-2020-2732 Paulo Bonzini discovered that the KVM implementation for Intel processors did not properly handle instruction emulation for L2 guests when nested virtualization is enabled. This could allow an L2 guest to cause privilege escalation, denial of service, or information leaks in the L1 guest.

- CVE-2020-8428 Al Viro discovered a use-after-free vulnerability in the VFS layer. This allowed local users to cause a denial-of-service (crash) or obtain sensitive information from kernel memory.

- CVE-2020-10942 It was discovered that the vhost_net driver did not properly validate the type of sockets set as back-ends.
A local user permitted to access /dev/vhost-net could use this to cause a stack corruption via crafted system calls, resulting in denial of service (crash) or possibly privilege escalation.

- CVE-2020-11565 Entropy Moe reported that the shared memory filesystem (tmpfs) did not correctly handle an 'mpol' mount option specifying an empty node list, leading to a stack-based out-of-bounds write. If user namespaces are enabled, a local user could use this to cause a denial of service (crash) or possibly for privilege escalation.

- CVE-2020-11884 Al Viro reported a race condition in memory management code for IBM Z (s390x architecture), that can result in the kernel executing code from the user address space. A local user could use this for privilege escalation.

Solution

Upgrade the linux packages.

For the stable distribution (buster), these problems have been fixed in version 4.19.98-1+deb10u1.

See Also

https://security-tracker.debian.org/tracker/CVE-2020-2732

https://security-tracker.debian.org/tracker/CVE-2020-8428

https://security-tracker.debian.org/tracker/CVE-2020-10942

https://security-tracker.debian.org/tracker/CVE-2020-11565

https://security-tracker.debian.org/tracker/CVE-2020-11884

https://security-tracker.debian.org/tracker/source-package/linux

https://packages.debian.org/source/buster/linux

https://www.debian.org/security/2020/dsa-4667

Plugin Details

Severity: Medium

ID: 136124

File Name: debian_DSA-4667.nasl

Version: 1.3

Type: local

Agent: unix

Published: 2020/04/30

Updated: 2020/05/08

Dependencies: 12634

Risk Information

Risk Factor: Medium

VPR Score: 6.7

CVSS Score Source: CVE-2020-11884

CVSS v2.0

Base Score: 6.9

Temporal Score: 5.1

Vector: CVSS2#AV:L/AC:M/Au:N/C:C/I:C/A:C

Temporal Vector: CVSS2#E:U/RL:OF/RC:C

CVSS v3.0

Base Score: 7

Temporal Score: 6.1

Vector: CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:debian:debian_linux:linux, cpe:/o:debian:debian_linux:10.0

Required KB Items: Host/local_checks_enabled, Host/Debian/release, Host/Debian/dpkg-l

Exploit Ease: No known exploits are available

Patch Publication Date: 2020/04/28

Vulnerability Publication Date: 2020/01/29

Reference Information

CVE: CVE-2020-10942, CVE-2020-11565, CVE-2020-11884, CVE-2020-2732, CVE-2020-8428

DSA: 4667