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
7.8 High
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
8.7 High
CVSS4
Attack Vector
LOCAL
Attack Complexity
HIGH
Privileges Required
LOW
User Interaction
NONE
CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/SC:H/VI:H/SI:H/VA:L/SA:L
8.5 High
AI Score
Confidence
High
0.001 Low
EPSS
Percentile
42.1%
The remote Ubuntu 20.04 LTS host has a package installed that is affected by multiple vulnerabilities as referenced in the USN-5106-1 advisory.
The Linux kernel through 5.8.13 does not properly enforce the Secure Boot Forbidden Signature Database (aka dbx) protection mechanism. This affects certs/blacklist.c and certs/system_keyring.c.
(CVE-2020-26541)
An issue was discovered in Linux: KVM through Improper handling of VM_IO|VM_PFNMAP vmas in KVM can bypass RO checks and can lead to pages being freed while still accessible by the VMM and guest. This allows users with the ability to start and control a VM to read/write random pages of memory and can result in local privilege escalation. (CVE-2021-22543)
An out-of-bounds memory write flaw was found in the Linux kernel’s joystick devices subsystem in versions before 5.9-rc1, in the way the user calls ioctl JSIOCSBTNMAP. This flaw allows a local user to crash the system or possibly escalate their privileges on the system. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability. (CVE-2021-3612)
In drivers/char/virtio_console.c in the Linux kernel before 5.13.4, data corruption or loss can be triggered by an untrusted device that supplies a buf->len value exceeding the buffer size. NOTE: the vendor indicates that the cited data corruption is not a vulnerability in any existing use case; the length validation was added solely for robustness in the face of anomalous host OS behavior (CVE-2021-38160)
fs/nfs/nfs4client.c in the Linux kernel before 5.13.4 has incorrect connection-setup ordering, which allows operators of remote NFSv4 servers to cause a denial of service (hanging of mounts) by arranging for those servers to be unreachable during trunking detection. (CVE-2021-38199)
loop_rw_iter in fs/io_uring.c in the Linux kernel 5.10 through 5.14.6 allows local users to gain privileges by using IORING_OP_PROVIDE_BUFFERS to trigger a free of a kernel buffer, as demonstrated by using /proc/<pid>/maps for exploitation. (CVE-2021-41073)
Note that Nessus has not tested for these issues but has instead relied only on the application’s self-reported version number.
#%NASL_MIN_LEVEL 70300
##
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-5106-1. The text
# itself is copyright (C) Canonical, Inc. See
# <https://ubuntu.com/security/notices>. Ubuntu(R) is a registered
# trademark of Canonical, Inc.
##
include('deprecated_nasl_level.inc');
include('compat.inc');
if (description)
{
script_id(153908);
script_version("1.5");
script_set_attribute(attribute:"plugin_modification_date", value:"2024/01/09");
script_cve_id(
"CVE-2020-26541",
"CVE-2021-3612",
"CVE-2021-22543",
"CVE-2021-38160",
"CVE-2021-38199",
"CVE-2021-41073"
);
script_xref(name:"USN", value:"5106-1");
script_name(english:"Ubuntu 20.04 LTS : Linux kernel (OEM) vulnerabilities (USN-5106-1)");
script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing one or more security updates.");
script_set_attribute(attribute:"description", value:
"The remote Ubuntu 20.04 LTS host has a package installed that is affected by multiple vulnerabilities as referenced in
the USN-5106-1 advisory.
- The Linux kernel through 5.8.13 does not properly enforce the Secure Boot Forbidden Signature Database
(aka dbx) protection mechanism. This affects certs/blacklist.c and certs/system_keyring.c.
(CVE-2020-26541)
- An issue was discovered in Linux: KVM through Improper handling of VM_IO|VM_PFNMAP vmas in KVM can bypass
RO checks and can lead to pages being freed while still accessible by the VMM and guest. This allows users
with the ability to start and control a VM to read/write random pages of memory and can result in local
privilege escalation. (CVE-2021-22543)
- An out-of-bounds memory write flaw was found in the Linux kernel's joystick devices subsystem in versions
before 5.9-rc1, in the way the user calls ioctl JSIOCSBTNMAP. This flaw allows a local user to crash the
system or possibly escalate their privileges on the system. The highest threat from this vulnerability is
to confidentiality, integrity, as well as system availability. (CVE-2021-3612)
- In drivers/char/virtio_console.c in the Linux kernel before 5.13.4, data corruption or loss can be
triggered by an untrusted device that supplies a buf->len value exceeding the buffer size. NOTE: the
vendor indicates that the cited data corruption is not a vulnerability in any existing use case; the
length validation was added solely for robustness in the face of anomalous host OS behavior
(CVE-2021-38160)
- fs/nfs/nfs4client.c in the Linux kernel before 5.13.4 has incorrect connection-setup ordering, which
allows operators of remote NFSv4 servers to cause a denial of service (hanging of mounts) by arranging for
those servers to be unreachable during trunking detection. (CVE-2021-38199)
- loop_rw_iter in fs/io_uring.c in the Linux kernel 5.10 through 5.14.6 allows local users to gain
privileges by using IORING_OP_PROVIDE_BUFFERS to trigger a free of a kernel buffer, as demonstrated by
using /proc/<pid>/maps for exploitation. (CVE-2021-41073)
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://ubuntu.com/security/notices/USN-5106-1");
script_set_attribute(attribute:"solution", value:
"Update the affected kernel package.");
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:U/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-2021-41073");
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:"2020/10/02");
script_set_attribute(attribute:"patch_publication_date", value:"2021/10/06");
script_set_attribute(attribute:"plugin_publication_date", value:"2021/10/07");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:20.04:-:lts");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-5.10.0-1049-oem");
script_set_attribute(attribute:"generated_plugin", value:"current");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_family(english:"Ubuntu Local Security Checks");
script_copyright(english:"Ubuntu Security Notice (C) 2021-2024 Canonical, Inc. / NASL script (C) 2021-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");
script_dependencies("ssh_get_info.nasl", "linux_alt_patch_detect.nasl");
script_require_keys("Host/cpu", "Host/Ubuntu", "Host/Ubuntu/release", "Host/Debian/dpkg-l");
exit(0);
}
include('debian_package.inc');
include('ksplice.inc');
if ( ! get_kb_item('Host/local_checks_enabled') ) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_release = get_kb_item('Host/Ubuntu/release');
if ( isnull(os_release) ) audit(AUDIT_OS_NOT, 'Ubuntu');
os_release = chomp(os_release);
if (! ('20.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 20.04', 'Ubuntu ' + os_release);
if ( ! get_kb_item('Host/Debian/dpkg-l') ) audit(AUDIT_PACKAGE_LIST_MISSING);
var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 's390' >!< cpu && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Ubuntu', cpu);
var kernel_mappings = {
'20.04': {
'5.10.0': {
'oem': '5.10.0-1049'
}
}
};
var host_kernel_release = get_kb_item('Host/uptrack-uname-r');
if (empty_or_null(host_kernel_release)) host_kernel_release = get_kb_item_or_exit('Host/uname-r');
var host_kernel_base_version = get_kb_item_or_exit('Host/Debian/kernel-base-version');
var host_kernel_type = get_kb_item_or_exit('Host/Debian/kernel-type');
if(empty_or_null(kernel_mappings[os_release][host_kernel_base_version][host_kernel_type])) audit(AUDIT_INST_VER_NOT_VULN, 'kernel ' + host_kernel_release);
var extra = '';
var kernel_fixed_version = kernel_mappings[os_release][host_kernel_base_version][host_kernel_type] + "-" + host_kernel_type;
if (deb_ver_cmp(ver1:host_kernel_release, ver2:kernel_fixed_version) < 0)
{
extra = extra + 'Running Kernel level of ' + host_kernel_release + ' does not meet the minimum fixed level of ' + kernel_fixed_version + ' for this advisory.\n\n';
}
else
{
audit(AUDIT_PATCH_INSTALLED, 'Kernel package for USN-5106-1');
}
if (get_one_kb_item('Host/ksplice/kernel-cves'))
{
var cve_list = make_list('CVE-2020-26541', 'CVE-2021-3612', 'CVE-2021-22543', 'CVE-2021-38160', 'CVE-2021-38199', 'CVE-2021-41073');
if (ksplice_cves_check(cve_list))
{
audit(AUDIT_PATCH_INSTALLED, 'KSplice hotfix for USN-5106-1');
}
else
{
extra = extra + ksplice_reporting_text();
}
}
if (extra) {
security_report_v4(
port : 0,
severity : SECURITY_HOLE,
extra : extra
);
exit(0);
}
Vendor | Product | Version | CPE |
---|---|---|---|
canonical | ubuntu_linux | 20.04 | cpe:/o:canonical:ubuntu_linux:20.04:-:lts |
canonical | ubuntu_linux | linux-image-5.10.0-1049-oem | p-cpe:/a:canonical:ubuntu_linux:linux-image-5.10.0-1049-oem |
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-26541
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-22543
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-3612
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-38160
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-38199
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-41073
ubuntu.com/security/notices/USN-5106-1
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
7.8 High
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
8.7 High
CVSS4
Attack Vector
LOCAL
Attack Complexity
HIGH
Privileges Required
LOW
User Interaction
NONE
CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/SC:H/VI:H/SI:H/VA:L/SA:L
8.5 High
AI Score
Confidence
High
0.001 Low
EPSS
Percentile
42.1%