Amazon Linux 2 : kernel (ALAS-2021-1600)

high Nessus Plugin ID 146631
New! Plugin Severity Now Using CVSS v3

The calculated severity for Plugins has been updated to use CVSS v3 by default. Plugins that do not have a CVSS v3 score will fall back to CVSS v2 for calculating severity. Severity display preferences can be toggled in the settings dropdown.

Synopsis

The remote Amazon Linux 2 host is missing a security update.

Description

The version of kernel installed on the remote host is prior to 4.14.219-161.340. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2021-1600 advisory.

- A use-after-free flaw was found in kernel/trace/ring_buffer.c in Linux kernel (before 5.10-rc1). There was a race problem in trace_open and resize of cpu buffer running parallely on different cpus, may cause a denial of service problem (DOS). This flaw could even allow a local attacker with special user privilege to a kernel information leak threat. (CVE-2020-27825)

- In drivers/target/target_core_xcopy.c in the Linux kernel before 5.10.7, insufficient identifier checking in the LIO SCSI target code can be used by remote attackers to read or write files via directory traversal in an XCOPY request, aka CID-2896c93811e3. For example, an attack can occur over a network if the attacker has access to one iSCSI LUN. The attacker gains control over file access because I/O operations are proxied via an attacker-selected backstore. (CVE-2020-28374)

- ** DISPUTED ** fs/nfsd/nfs3xdr.c in the Linux kernel through 5.10.8, when there is an NFS export of a subdirectory of a filesystem, allows remote attackers to traverse to other parts of the filesystem via READDIRPLUS. NOTE: some parties argue that such a subdirectory export is not intended to prevent this attack; see also the exports(5) no_subtree_check default behavior. (CVE-2021-3178)

- An issue was discovered in the Linux kernel through 5.10.11. PI futexes have a kernel stack use-after-free during fault handling, allowing local users to execute code in the kernel, aka CID-34b1a1ce1458.
(CVE-2021-3347)

- nbd_add_socket in drivers/block/nbd.c in the Linux kernel through 5.10.12 has an ndb_queue_rq use-after- free that could be triggered by local attackers (with access to the nbd device) via an I/O request at a certain point during device setup, aka CID-b98e762e3d71. (CVE-2021-3348)

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

Solution

Run 'yum update kernel' to update your system.

See Also

https://alas.aws.amazon.com/AL2/ALAS-2021-1600.html

https://access.redhat.com/security/cve/CVE-2020-27825

https://access.redhat.com/security/cve/CVE-2020-28374

https://access.redhat.com/security/cve/CVE-2021-3178

https://access.redhat.com/security/cve/CVE-2021-3347

https://access.redhat.com/security/cve/CVE-2021-3348

Plugin Details

Severity: High

ID: 146631

File Name: al2_ALAS-2021-1600.nasl

Version: 1.2

Type: local

Agent: unix

Published: 2/19/2021

Updated: 2/19/2021

Dependencies: ssh_get_info.nasl

Risk Information

CVSS Score Source: CVE-2021-3347

VPR

Risk Factor: High

Score: 8.4

CVSS v2

Risk Factor: High

Base Score: 7.2

Temporal Score: 5.3

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

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

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.8

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

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

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:kernel, p-cpe:/a:amazon:linux:kernel-debuginfo, p-cpe:/a:amazon:linux:kernel-debuginfo-common-aarch64, p-cpe:/a:amazon:linux:kernel-debuginfo-common-x86_64, p-cpe:/a:amazon:linux:kernel-devel, p-cpe:/a:amazon:linux:kernel-headers, p-cpe:/a:amazon:linux:kernel-livepatch-4.14.219-161.340, p-cpe:/a:amazon:linux:kernel-tools, p-cpe:/a:amazon:linux:kernel-tools-debuginfo, p-cpe:/a:amazon:linux:kernel-tools-devel, p-cpe:/a:amazon:linux:perf, p-cpe:/a:amazon:linux:perf-debuginfo, p-cpe:/a:amazon:linux:python-perf, p-cpe:/a:amazon:linux:python-perf-debuginfo, cpe:/o:amazon:linux:2

Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list

Exploit Ease: No known exploits are available

Patch Publication Date: 2/17/2021

Vulnerability Publication Date: 12/11/2020

Reference Information

CVE: CVE-2020-27825, CVE-2020-28374, CVE-2021-3178, CVE-2021-3347, CVE-2021-3348

ALAS: 2021-1600