Ubuntu 20.04 LTS : Linux kernel vulnerabilities (USN-4367-1)

high Nessus Plugin ID 136732

Synopsis

The remote Ubuntu host is missing one or more security updates.

Description

The remote Ubuntu 20.04 LTS host has a package installed that is affected by multiple vulnerabilities as referenced in the USN-4367-1 advisory.

- In the Linux kernel 5.0.21, mounting a crafted btrfs filesystem image, performing some operations, and unmounting can lead to a use-after-free in btrfs_queue_work in fs/btrfs/async-thread.c. (CVE-2019-19377)

- An issue was discovered in the Linux kernel through 5.6.2. mpol_parse_str in mm/mempolicy.c has a stack- based out-of-bounds write because an empty nodelist is mishandled during mount option parsing, aka CID- aa9f7d5172fa. NOTE: Someone in the security community disagrees that this is a vulnerability because the issue is a bug in parsing mount options which can only be specified by a privileged user, so triggering the bug does not grant any powers not already held. (CVE-2020-11565)

- An issue was discovered in the Linux kernel before 5.6.5. There is a use-after-free in block/bfq-iosched.c related to bfq_idle_slice_timer_body. (CVE-2020-12657)

- A signal access-control issue was discovered in the Linux kernel before 5.6.5, aka CID-7395ea4e65c2.
Because exec_id in include/linux/sched.h is only 32 bits, an integer overflow can interfere with a do_notify_parent protection mechanism. A child process can send an arbitrary signal to a parent process in a different security domain. Exploitation limitations include the amount of elapsed time before an integer overflow occurs, and the lack of scenarios where signals to a parent process present a substantial operational threat. (CVE-2020-12826)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Update the affected kernel package.

See Also

https://ubuntu.com/security/notices/USN-4367-1

Plugin Details

Severity: High

ID: 136732

File Name: ubuntu_USN-4367-1.nasl

Version: 1.9

Type: local

Agent: unix

Published: 5/20/2020

Updated: 1/9/2024

Supported Sensors: Agentless Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5.3

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

CVSS Score Source: CVE-2019-19377

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 7

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

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

CVSS Score Source: CVE-2020-12657

Vulnerability Information

CPE: p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1011-aws, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1011-gcp, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1011-kvm, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1011-oracle, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1011-raspi, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1012-azure, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-26-generic, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-31-generic, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-31-generic-lpae, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-31-lowlatency, cpe:/o:canonical:ubuntu_linux:20.04:-:lts

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

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 5/24/2020

Vulnerability Publication Date: 11/29/2019

Reference Information

CVE: CVE-2019-19377, CVE-2020-11565, CVE-2020-12657, CVE-2020-12826

USN: 4367-1