Ubuntu 16.04 LTS / 18.04 LTS : Linux kernel vulnerabilities (USN-4680-1)

high Nessus Plugin ID 144749

Synopsis

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

Description

The remote Ubuntu 16.04 LTS / 18.04 LTS host has a package installed that is affected by multiple vulnerabilities as referenced in the USN-4680-1 advisory.

- In the Linux kernel 4.19.83, there is a use-after-free (read) in the debugfs_remove function in fs/debugfs/inode.c (which is used to remove a file or directory in debugfs that was previously created with a call to another debugfs function such as debugfs_create_file). NOTE: Linux kernel developers dispute this issue as not being an issue with debugfs, instead this is an issue with misuse of debugfs within blktrace (CVE-2019-19770)

- In binder_release_work of binder.c, there is a possible use-after-free due to improper locking. This could lead to local escalation of privilege in the kernel with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android kernelAndroid ID:
A-161151868References: N/A (CVE-2020-0423)

- Legacy pairing and secure-connections pairing authentication in Bluetooth BR/EDR Core Specification v5.2 and earlier may allow an unauthenticated user to complete authentication without pairing credentials via adjacent access. An unauthenticated, adjacent attacker could impersonate a Bluetooth BR/EDR master or slave to pair with a previously paired remote device to successfully complete the authentication procedure without knowing the link key. (CVE-2020-10135)

- A flaw was found in the Linux kernel. A use-after-free was found in the way the console subsystem was using ioctls KDGKBSENT and KDSKBSENT. A local user could use this flaw to get read memory access out of bounds. The highest threat from this vulnerability is to data confidentiality. (CVE-2020-25656)

- A flaw was found in Linux Kernel because access to the global variable fg_console is not properly synchronized leading to a use after free in con_font_op. (CVE-2020-25668)

- A flaw in ICMP packets in the Linux kernel may allow an attacker to quickly scan open UDP ports. This flaw allows an off-path remote attacker to effectively bypass source port UDP randomization. Software that relies on UDP source port randomization are indirectly affected as well on the Linux Based Products (RUGGEDCOM RM1224: All versions between v5.0 and v6.4, SCALANCE M-800: All versions between v5.0 and v6.4, SCALANCE S615: All versions between v5.0 and v6.4, SCALANCE SC-600: All versions prior to v2.1.3, SCALANCE W1750D: v8.3.0.1, v8.6.0, and v8.7.0, SIMATIC Cloud Connect 7: All versions, SIMATIC MV500 Family: All versions, SIMATIC NET CP 1243-1 (incl. SIPLUS variants): Versions 3.1.39 and later, SIMATIC NET CP 1243-7 LTE EU: Version (CVE-2020-25705)

- An issue was discovered in the Linux kernel through 5.9.1, as used with Xen through 4.14.x.
drivers/xen/events/events_base.c allows event-channel removal during the event-handling loop (a race condition). This can cause a use-after-free or NULL pointer dereference, as demonstrated by a dom0 crash via events for an in-reconfiguration paravirtualized device, aka CID-073d0552ead5. (CVE-2020-27675)

- A flaw was found in the way RTAS handled memory accesses in userspace to kernel communication. On a locked down (usually due to Secure Boot) guest system running on top of PowerVM or KVM hypervisors (pseries platform) a root like local user could use this flaw to further increase their privileges to that of a running kernel. (CVE-2020-27777)

- A slab-out-of-bounds read in fbcon in the Linux kernel before 5.9.7 could be used by local attackers to read privileged information or potentially crash the kernel, aka CID-3c4e0dff2095. This occurs because KD_FONT_OP_COPY in drivers/tty/vt/vt.c can be used for manipulations such as font height. (CVE-2020-28974)

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-4680-1

Plugin Details

Severity: High

ID: 144749

File Name: ubuntu_USN-4680-1.nasl

Version: 1.9

Type: local

Agent: unix

Published: 1/6/2021

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: High

Base Score: 7.2

Temporal Score: 5.6

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

CVSS Score Source: CVE-2020-27777

CVSS v3

Risk Factor: High

Base Score: 8.2

Temporal Score: 7.4

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

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

CVSS Score Source: CVE-2019-19770

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:16.04:-:lts, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1062-oracle, p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1077-gke, p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1077-raspi2, p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1082-kvm, p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1091-aws, p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1094-snapdragon, p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1103-azure, p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-129-generic, p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-129-generic-lpae, p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-129-lowlatency

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: 1/6/2021

Vulnerability Publication Date: 12/12/2019

Reference Information

CVE: CVE-2019-19770, CVE-2020-0423, CVE-2020-10135, CVE-2020-25656, CVE-2020-25668, CVE-2020-25705, CVE-2020-27675, CVE-2020-27777, CVE-2020-28974

USN: 4680-1