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
8.8 High
AI Score
Confidence
High
0.001 Low
EPSS
Percentile
23.7%
The remote Oracle Linux 7 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2021-9419 advisory.
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)
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)
Note that Nessus has not tested for this issue 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 Oracle Linux Security Advisory ELSA-2021-9419.
##
include('deprecated_nasl_level.inc');
include('compat.inc');
if (description)
{
script_id(152601);
script_version("1.7");
script_set_attribute(attribute:"plugin_modification_date", value:"2023/12/04");
script_cve_id("CVE-2021-3653", "CVE-2021-3656");
script_name(english:"Oracle Linux 7 : Unbreakable Enterprise kernel (ELSA-2021-9419)");
script_set_attribute(attribute:"synopsis", value:
"The remote Oracle Linux host is missing one or more security updates.");
script_set_attribute(attribute:"description", value:
"The remote Oracle Linux 7 host has packages installed that are affected by multiple vulnerabilities as referenced in the
ELSA-2021-9419 advisory.
- 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)
- 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)
Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
script_set_attribute(attribute:"see_also", value:"https://linux.oracle.com/errata/ELSA-2021-9419.html");
script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
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-2021-3656");
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:"2021/08/16");
script_set_attribute(attribute:"patch_publication_date", value:"2021/08/16");
script_set_attribute(attribute:"plugin_publication_date", value:"2021/08/16");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"cpe:/o:oracle:linux:7");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-debug");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-debug-devel");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-devel");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-doc");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-headers");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-tools");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-tools-libs");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-tools-libs-devel");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:perf");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:python-perf");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_family(english:"Oracle Linux Local Security Checks");
script_copyright(english:"This script is Copyright (C) 2021-2023 and is owned by Tenable, Inc. or an Affiliate thereof.");
script_dependencies("linux_alt_patch_detect.nasl", "ssh_get_info.nasl");
script_require_keys("Host/OracleLinux", "Host/RedHat/release", "Host/RedHat/rpm-list", "Host/local_checks_enabled");
exit(0);
}
include('audit.inc');
include('global_settings.inc');
include('ksplice.inc');
include('rpm.inc');
if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item('Host/OracleLinux')) audit(AUDIT_OS_NOT, 'Oracle Linux');
var release = get_kb_item("Host/RedHat/release");
if (isnull(release) || !pregmatch(pattern: "Oracle (?:Linux Server|Enterprise Linux)", string:release)) audit(AUDIT_OS_NOT, 'Oracle Linux');
var os_ver = pregmatch(pattern: "Oracle (?:Linux Server|Enterprise Linux) .*release ([0-9]+(\.[0-9]+)?)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'Oracle Linux');
var os_ver = os_ver[1];
if (! preg(pattern:"^7([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, 'Oracle Linux 7', 'Oracle Linux ' + os_ver);
if (!get_kb_item('Host/RedHat/rpm-list')) audit(AUDIT_PACKAGE_LIST_MISSING);
var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Oracle Linux', cpu);
var machine_uptrack_level = get_one_kb_item('Host/uptrack-uname-r');
if (machine_uptrack_level)
{
var trimmed_uptrack_level = ereg_replace(string:machine_uptrack_level, pattern:"\.(x86_64|i[3-6]86|aarch64)$", replace:'');
var fixed_uptrack_levels = ['4.14.35-2047.506.10.el7uek'];
foreach var fixed_uptrack_level ( fixed_uptrack_levels ) {
if (rpm_spec_vers_cmp(a:trimmed_uptrack_level, b:fixed_uptrack_level) >= 0)
{
audit(AUDIT_PATCH_INSTALLED, 'KSplice hotfix for ELSA-2021-9419');
}
}
__rpm_report = 'Running KSplice level of ' + trimmed_uptrack_level + ' does not meet the minimum fixed level of ' + join(fixed_uptrack_levels, sep:' / ') + ' for this advisory.\n\n';
}
var kernel_major_minor = get_kb_item('Host/uname/major_minor');
if (empty_or_null(kernel_major_minor)) exit(1, 'Unable to determine kernel major-minor level.');
var expected_kernel_major_minor = '4.14';
if (kernel_major_minor != expected_kernel_major_minor)
audit(AUDIT_OS_NOT, 'running kernel level ' + expected_kernel_major_minor + ', it is running kernel level ' + kernel_major_minor);
var pkgs = [
{'reference':'kernel-uek-4.14.35-2047.506.10.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-4.14.35'},
{'reference':'kernel-uek-4.14.35-2047.506.10.el7uek', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-4.14.35'},
{'reference':'kernel-uek-debug-4.14.35-2047.506.10.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-debug-4.14.35'},
{'reference':'kernel-uek-debug-4.14.35-2047.506.10.el7uek', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-debug-4.14.35'},
{'reference':'kernel-uek-debug-devel-4.14.35-2047.506.10.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-debug-devel-4.14.35'},
{'reference':'kernel-uek-debug-devel-4.14.35-2047.506.10.el7uek', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-debug-devel-4.14.35'},
{'reference':'kernel-uek-devel-4.14.35-2047.506.10.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-devel-4.14.35'},
{'reference':'kernel-uek-devel-4.14.35-2047.506.10.el7uek', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-devel-4.14.35'},
{'reference':'kernel-uek-doc-4.14.35-2047.506.10.el7uek', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-doc-4.14.35'},
{'reference':'kernel-uek-headers-4.14.35-2047.506.10.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-headers-4.14.35'},
{'reference':'kernel-uek-tools-4.14.35-2047.506.10.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-tools-4.14.35'},
{'reference':'kernel-uek-tools-4.14.35-2047.506.10.el7uek', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-tools-4.14.35'},
{'reference':'kernel-uek-tools-libs-4.14.35-2047.506.10.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-tools-libs-4.14.35'},
{'reference':'kernel-uek-tools-libs-devel-4.14.35-2047.506.10.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-tools-libs-devel-4.14.35'},
{'reference':'perf-4.14.35-2047.506.10.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE},
{'reference':'python-perf-4.14.35-2047.506.10.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE}
];
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 = 'EL' + 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) {
if (exists_check) {
if (rpm_exists(release:release, rpm:exists_check) && 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++;
} else {
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-uek / kernel-uek-debug / kernel-uek-debug-devel / etc');
}
Vendor | Product | Version | CPE |
---|---|---|---|
oracle | linux | 7 | cpe:/o:oracle:linux:7 |
oracle | linux | kernel-uek | p-cpe:/a:oracle:linux:kernel-uek |
oracle | linux | kernel-uek-debug | p-cpe:/a:oracle:linux:kernel-uek-debug |
oracle | linux | kernel-uek-debug-devel | p-cpe:/a:oracle:linux:kernel-uek-debug-devel |
oracle | linux | kernel-uek-devel | p-cpe:/a:oracle:linux:kernel-uek-devel |
oracle | linux | kernel-uek-doc | p-cpe:/a:oracle:linux:kernel-uek-doc |
oracle | linux | kernel-uek-headers | p-cpe:/a:oracle:linux:kernel-uek-headers |
oracle | linux | kernel-uek-tools | p-cpe:/a:oracle:linux:kernel-uek-tools |
oracle | linux | kernel-uek-tools-libs | p-cpe:/a:oracle:linux:kernel-uek-tools-libs |
oracle | linux | kernel-uek-tools-libs-devel | p-cpe:/a:oracle:linux:kernel-uek-tools-libs-devel |
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
8.8 High
AI Score
Confidence
High
0.001 Low
EPSS
Percentile
23.7%