7.2 High
CVSS2
Attack Vector
LOCAL
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:L/AC:L/Au:N/C:C/I:C/A:C
8.8 High
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
0.004 Low
EPSS
Percentile
72.9%
The version of kernel installed on the remote host is prior to 5.4.91-41.139. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2KERNEL-5.4-2022-019 advisory.
A flaw was found in the JFS filesystem code in the Linux Kernel which allows a local attacker with the ability to set extended attributes to panic the system, causing memory corruption or escalating privileges. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability. (CVE-2020-27815)
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)
An issue was discovered in Xen through 4.14.x. Some OSes (such as Linux, FreeBSD, and NetBSD) are processing watch events using a single thread. If the events are received faster than the thread is able to handle, they will get queued. As the queue is unbounded, a guest may be able to trigger an OOM in the backend. All systems with a FreeBSD, Linux, or NetBSD (any version) dom0 are vulnerable. (CVE-2020-29568)
An issue was discovered in the Linux kernel through 5.10.1, as used with Xen through 4.14.x. The Linux kernel PV block backend expects the kernel thread handler to reset ring->xenblkd to NULL when stopped.
However, the handler may not have time to run if the frontend quickly toggles between the states connect and disconnect. As a consequence, the block backend may re-use a pointer after it was freed. A misbehaving guest can trigger a dom0 crash by continuously connecting / disconnecting a block frontend. Privilege escalation and information leaks cannot be ruled out. This only affects systems with a Linux blkback.
(CVE-2020-29569)
A locking inconsistency issue was discovered in the tty subsystem of the Linux kernel through 5.9.13.
drivers/tty/tty_io.c and drivers/tty/tty_jobctrl.c may allow a read-after-free attack against TIOCGSID, aka CID-c8bcd9c5be24. (CVE-2020-29660)
A locking issue was discovered in the tty subsystem of the Linux kernel through 5.9.13.
drivers/tty/tty_jobctrl.c allows a use-after-free attack against TIOCSPGRP, aka CID-54ffccbf053b.
(CVE-2020-29661)
Note that Nessus has not tested for these issues but has instead relied only on the application’s self-reported version number.
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux 2 Security Advisory ALASKERNEL-5.4-2022-019.
##
include('compat.inc');
if (description)
{
script_id(160430);
script_version("1.8");
script_set_attribute(attribute:"plugin_modification_date", value:"2023/09/05");
script_cve_id(
"CVE-2020-27815",
"CVE-2020-28374",
"CVE-2020-29568",
"CVE-2020-29569",
"CVE-2020-29660",
"CVE-2020-29661",
"CVE-2021-39648"
);
script_xref(name:"IAVB", value:"2020-B-0077-S");
script_name(english:"Amazon Linux 2 : kernel (ALASKERNEL-5.4-2022-019)");
script_set_attribute(attribute:"synopsis", value:
"The remote Amazon Linux 2 host is missing a security update.");
script_set_attribute(attribute:"description", value:
"The version of kernel installed on the remote host is prior to 5.4.91-41.139. It is, therefore, affected by multiple
vulnerabilities as referenced in the ALAS2KERNEL-5.4-2022-019 advisory.
- A flaw was found in the JFS filesystem code in the Linux Kernel which allows a local attacker with the
ability to set extended attributes to panic the system, causing memory corruption or escalating
privileges. The highest threat from this vulnerability is to confidentiality, integrity, as well as system
availability. (CVE-2020-27815)
- 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)
- An issue was discovered in Xen through 4.14.x. Some OSes (such as Linux, FreeBSD, and NetBSD) are
processing watch events using a single thread. If the events are received faster than the thread is able
to handle, they will get queued. As the queue is unbounded, a guest may be able to trigger an OOM in the
backend. All systems with a FreeBSD, Linux, or NetBSD (any version) dom0 are vulnerable. (CVE-2020-29568)
- An issue was discovered in the Linux kernel through 5.10.1, as used with Xen through 4.14.x. The Linux
kernel PV block backend expects the kernel thread handler to reset ring->xenblkd to NULL when stopped.
However, the handler may not have time to run if the frontend quickly toggles between the states connect
and disconnect. As a consequence, the block backend may re-use a pointer after it was freed. A misbehaving
guest can trigger a dom0 crash by continuously connecting / disconnecting a block frontend. Privilege
escalation and information leaks cannot be ruled out. This only affects systems with a Linux blkback.
(CVE-2020-29569)
- A locking inconsistency issue was discovered in the tty subsystem of the Linux kernel through 5.9.13.
drivers/tty/tty_io.c and drivers/tty/tty_jobctrl.c may allow a read-after-free attack against TIOCGSID,
aka CID-c8bcd9c5be24. (CVE-2020-29660)
- A locking issue was discovered in the tty subsystem of the Linux kernel through 5.9.13.
drivers/tty/tty_jobctrl.c allows a use-after-free attack against TIOCSPGRP, aka CID-54ffccbf053b.
(CVE-2020-29661)
Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/AL2/ALASKERNEL-5.4-2022-019.html");
script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2020-27815.html");
script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2020-28374.html");
script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2020-29568.html");
script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2020-29569.html");
script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2020-29660.html");
script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2020-29661.html");
script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-39648.html");
script_set_attribute(attribute:"solution", value:
"Run 'yum update kernel' to update your system.");
script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C");
script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H");
script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-29661");
script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2020-29569");
script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
script_set_attribute(attribute:"exploit_available", value:"true");
script_set_attribute(attribute:"vuln_publication_date", value:"2020/12/03");
script_set_attribute(attribute:"patch_publication_date", value:"2022/01/20");
script_set_attribute(attribute:"plugin_publication_date", value:"2022/05/02");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-debuginfo");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-debuginfo-common-aarch64");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-debuginfo-common-x86_64");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-devel");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-headers");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-tools");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-tools-debuginfo");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-tools-devel");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:perf");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:perf-debuginfo");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:python-perf");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:python-perf-debuginfo");
script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux:2");
script_set_attribute(attribute:"stig_severity", value:"II");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_family(english:"Amazon Linux Local Security Checks");
script_copyright(english:"This script is Copyright (C) 2022-2023 and is owned by Tenable, Inc. or an Affiliate thereof.");
script_dependencies("kpatch.nasl", "ssh_get_info.nasl");
script_require_keys("Host/local_checks_enabled", "Host/AmazonLinux/release", "Host/AmazonLinux/rpm-list");
exit(0);
}
include("rpm.inc");
include("hotfixes.inc");
if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var alas_release = get_kb_item("Host/AmazonLinux/release");
if (isnull(alas_release) || !strlen(alas_release)) audit(AUDIT_OS_NOT, "Amazon Linux");
var os_ver = pregmatch(pattern: "^AL(A|\d+|-\d+)", string:alas_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Amazon Linux");
os_ver = os_ver[1];
if (os_ver != "2")
{
if (os_ver == 'A') os_ver = 'AMI';
audit(AUDIT_OS_NOT, "Amazon Linux 2", "Amazon Linux " + os_ver);
}
if (!get_kb_item("Host/AmazonLinux/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);
if (get_one_kb_item("Host/kpatch/kernel-cves"))
{
set_hotfix_type("kpatch");
var cve_list = make_list("CVE-2020-27815", "CVE-2020-28374", "CVE-2020-29568", "CVE-2020-29569", "CVE-2020-29660", "CVE-2020-29661", "CVE-2021-39648");
if (hotfix_cves_check(cve_list))
{
audit(AUDIT_PATCH_INSTALLED, "kpatch hotfix for ALASKERNEL-5.4-2022-019");
}
else
{
__rpm_report = hotfix_reporting_text();
}
}
var pkgs = [
{'reference':'kernel-5.4.91-41.139.amzn2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-5.4.91-41.139.amzn2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-debuginfo-5.4.91-41.139.amzn2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-debuginfo-5.4.91-41.139.amzn2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-debuginfo-common-aarch64-5.4.91-41.139.amzn2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-debuginfo-common-x86_64-5.4.91-41.139.amzn2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-devel-5.4.91-41.139.amzn2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-devel-5.4.91-41.139.amzn2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-headers-5.4.91-41.139.amzn2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-headers-5.4.91-41.139.amzn2', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-headers-5.4.91-41.139.amzn2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-tools-5.4.91-41.139.amzn2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-tools-5.4.91-41.139.amzn2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-tools-debuginfo-5.4.91-41.139.amzn2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-tools-debuginfo-5.4.91-41.139.amzn2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-tools-devel-5.4.91-41.139.amzn2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'kernel-tools-devel-5.4.91-41.139.amzn2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'perf-5.4.91-41.139.amzn2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'perf-5.4.91-41.139.amzn2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'perf-debuginfo-5.4.91-41.139.amzn2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'perf-debuginfo-5.4.91-41.139.amzn2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'python-perf-5.4.91-41.139.amzn2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'python-perf-5.4.91-41.139.amzn2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'python-perf-debuginfo-5.4.91-41.139.amzn2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'},
{'reference':'python-perf-debuginfo-5.4.91-41.139.amzn2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-5.4'}
];
var flag = 0;
foreach var package_array ( pkgs ) {
var reference = NULL;
var _release = NULL;
var sp = NULL;
var _cpu = NULL;
var el_string = NULL;
var rpm_spec_vers_cmp = NULL;
var epoch = NULL;
var allowmaj = NULL;
var exists_check = NULL;
if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
if (!empty_or_null(package_array['release'])) _release = package_array['release'];
if (!empty_or_null(package_array['sp'])) sp = package_array['sp'];
if (!empty_or_null(package_array['cpu'])) _cpu = package_array['cpu'];
if (!empty_or_null(package_array['el_string'])) el_string = package_array['el_string'];
if (!empty_or_null(package_array['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = package_array['rpm_spec_vers_cmp'];
if (!empty_or_null(package_array['epoch'])) epoch = package_array['epoch'];
if (!empty_or_null(package_array['allowmaj'])) allowmaj = package_array['allowmaj'];
if (!empty_or_null(package_array['exists_check'])) exists_check = package_array['exists_check'];
if (reference && _release && (!exists_check || rpm_exists(release:_release, rpm:exists_check))) {
if (rpm_check(release:_release, sp:sp, cpu:_cpu, reference:reference, epoch:epoch, el_string:el_string, rpm_spec_vers_cmp:rpm_spec_vers_cmp, allowmaj:allowmaj)) flag++;
}
}
if (flag)
{
security_report_v4(
port : 0,
severity : SECURITY_HOLE,
extra : rpm_report_get()
);
exit(0);
}
else
{
var tested = pkg_tests_get();
if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
else audit(AUDIT_PACKAGE_NOT_INSTALLED, "kernel / kernel-debuginfo / kernel-debuginfo-common-x86_64 / etc");
}
Vendor | Product | Version | CPE |
---|---|---|---|
amazon | linux | kernel | p-cpe:/a:amazon:linux:kernel |
amazon | linux | kernel-debuginfo | p-cpe:/a:amazon:linux:kernel-debuginfo |
amazon | linux | kernel-debuginfo-common-aarch64 | p-cpe:/a:amazon:linux:kernel-debuginfo-common-aarch64 |
amazon | linux | kernel-debuginfo-common-x86_64 | p-cpe:/a:amazon:linux:kernel-debuginfo-common-x86_64 |
amazon | linux | kernel-devel | p-cpe:/a:amazon:linux:kernel-devel |
amazon | linux | kernel-headers | p-cpe:/a:amazon:linux:kernel-headers |
amazon | linux | kernel-tools | p-cpe:/a:amazon:linux:kernel-tools |
amazon | linux | kernel-tools-debuginfo | p-cpe:/a:amazon:linux:kernel-tools-debuginfo |
amazon | linux | kernel-tools-devel | p-cpe:/a:amazon:linux:kernel-tools-devel |
amazon | linux | perf | p-cpe:/a:amazon:linux:perf |
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-27815
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-28374
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-29568
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-29569
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-29660
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-29661
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-39648
alas.aws.amazon.com/AL2/ALASKERNEL-5.4-2022-019.html
alas.aws.amazon.com/cve/html/CVE-2020-27815.html
alas.aws.amazon.com/cve/html/CVE-2020-28374.html
alas.aws.amazon.com/cve/html/CVE-2020-29568.html
alas.aws.amazon.com/cve/html/CVE-2020-29569.html
alas.aws.amazon.com/cve/html/CVE-2020-29660.html
alas.aws.amazon.com/cve/html/CVE-2020-29661.html
alas.aws.amazon.com/cve/html/CVE-2021-39648.html
7.2 High
CVSS2
Attack Vector
LOCAL
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:L/AC:L/Au:N/C:C/I:C/A:C
8.8 High
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
0.004 Low
EPSS
Percentile
72.9%