The remote Ubuntu 16.04 ESM / 18.04 LTS host has a package installed that is affected by multiple vulnerabilities as referenced in the USN-5073-1 advisory.
net/can/bcm.c in the Linux kernel through 5.12.10 allows local users to obtain sensitive information from kernel stack memory because parts of a data structure are uninitialized. (CVE-2021-34693)
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)
A flaw was found in the KVM’s AMD code for supporting SVM nested virtualization. The flaw occurs when processing the VMCB (virtual machine control block) provided by the L1 guest to spawn/handle a nested guest (L2). Due to improper validation of the int_ctl field, this issue could allow a malicious L1 to enable AVIC support (Advanced Virtual Interrupt Controller) for the L2 guest. As a result, the L2 guest would be allowed to read/write physical pages of the host, resulting in a crash of the entire system, leak of sensitive data or potential guest-to-host escape. This flaw affects Linux kernel versions prior to 5.14-rc7. (CVE-2021-3653)
A flaw was found in the KVM’s AMD code for supporting SVM nested virtualization. The flaw occurs when processing the VMCB (virtual machine control block) provided by the L1 guest to spawn/handle a nested guest (L2). Due to improper validation of the virt_ext field, this issue could allow a malicious L1 to disable both VMLOAD/VMSAVE intercepts and VLS (Virtual VMLOAD/VMSAVE) for the L2 guest. As a result, the L2 guest would be allowed to read/write physical pages of the host, resulting in a crash of the entire system, leak of sensitive data or potential guest-to-host escape. (CVE-2021-3656)
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)
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-5073-1. 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(153177);
script_version("1.10");
script_set_attribute(attribute:"plugin_modification_date", value:"2024/01/09");
script_cve_id(
"CVE-2021-3612",
"CVE-2021-3653",
"CVE-2021-3656",
"CVE-2021-34693",
"CVE-2021-38160"
);
script_xref(name:"USN", value:"5073-1");
script_name(english:"Ubuntu 16.04 ESM / 18.04 LTS : Linux kernel vulnerabilities (USN-5073-1)");
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 16.04 ESM / 18.04 LTS host has a package installed that is affected by multiple vulnerabilities as
referenced in the USN-5073-1 advisory.
- net/can/bcm.c in the Linux kernel through 5.12.10 allows local users to obtain sensitive information from
kernel stack memory because parts of a data structure are uninitialized. (CVE-2021-34693)
- 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)
- A flaw was found in the KVM's AMD code for supporting SVM nested virtualization. The flaw occurs when
processing the VMCB (virtual machine control block) provided by the L1 guest to spawn/handle a nested
guest (L2). Due to improper validation of the int_ctl field, this issue could allow a malicious L1 to
enable AVIC support (Advanced Virtual Interrupt Controller) for the L2 guest. As a result, the L2 guest
would be allowed to read/write physical pages of the host, resulting in a crash of the entire system, leak
of sensitive data or potential guest-to-host escape. This flaw affects Linux kernel versions prior to
5.14-rc7. (CVE-2021-3653)
- A flaw was found in the KVM's AMD code for supporting SVM nested virtualization. The flaw occurs when
processing the VMCB (virtual machine control block) provided by the L1 guest to spawn/handle a nested
guest (L2). Due to improper validation of the virt_ext field, this issue could allow a malicious L1 to
disable both VMLOAD/VMSAVE intercepts and VLS (Virtual VMLOAD/VMSAVE) for the L2 guest. As a result, the
L2 guest would be allowed to read/write physical pages of the host, resulting in a crash of the entire
system, leak of sensitive data or potential guest-to-host escape. (CVE-2021-3656)
- 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)
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-5073-1");
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: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-2021-38160");
script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2021-3656");
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:"2021/06/14");
script_set_attribute(attribute:"patch_publication_date", value:"2021/09/09");
script_set_attribute(attribute:"plugin_publication_date", value:"2021/09/09");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:16.04:-:esm");
script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:18.04:-:lts");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1027-dell300x");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1080-oracle");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1099-kvm");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1111-aws");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1112-snapdragon");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1123-azure");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-156-generic");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-156-generic-lpae");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-156-lowlatency");
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 (! ('16.04' >< os_release || '18.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 16.04 / 18.04', '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 = {
'16.04': {
'4.15.0': {
'generic': '4.15.0-156',
'lowlatency': '4.15.0-156',
'oracle': '4.15.0-1080',
'aws': '4.15.0-1111',
'azure': '4.15.0-1123'
}
},
'18.04': {
'4.15.0': {
'generic': '4.15.0-156',
'generic-lpae': '4.15.0-156',
'lowlatency': '4.15.0-156',
'dell300x': '4.15.0-1027',
'oracle': '4.15.0-1080',
'kvm': '4.15.0-1099',
'aws': '4.15.0-1111',
'snapdragon': '4.15.0-1112',
'azure': '4.15.0-1123'
}
}
};
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-5073-1');
}
if (get_one_kb_item('Host/ksplice/kernel-cves'))
{
var cve_list = make_list('CVE-2021-3612', 'CVE-2021-3653', 'CVE-2021-3656', 'CVE-2021-34693', 'CVE-2021-38160');
if (ksplice_cves_check(cve_list))
{
audit(AUDIT_PATCH_INSTALLED, 'KSplice hotfix for USN-5073-1');
}
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 | 16.04 | cpe:/o:canonical:ubuntu_linux:16.04:-:esm |
canonical | ubuntu_linux | 18.04 | cpe:/o:canonical:ubuntu_linux:18.04:-:lts |
canonical | ubuntu_linux | linux-image-4.15.0-1027-dell300x | p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1027-dell300x |
canonical | ubuntu_linux | linux-image-4.15.0-1080-oracle | p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1080-oracle |
canonical | ubuntu_linux | linux-image-4.15.0-1099-kvm | p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1099-kvm |
canonical | ubuntu_linux | linux-image-4.15.0-1111-aws | p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1111-aws |
canonical | ubuntu_linux | linux-image-4.15.0-1112-snapdragon | p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1112-snapdragon |
canonical | ubuntu_linux | linux-image-4.15.0-1123-azure | p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1123-azure |
canonical | ubuntu_linux | linux-image-4.15.0-156-generic | p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-156-generic |
canonical | ubuntu_linux | linux-image-4.15.0-156-generic-lpae | p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-156-generic-lpae |
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-34693
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-3612
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-3653
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-3656
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-38160
ubuntu.com/security/notices/USN-5073-1