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nessusThis script is Copyright (C) 2022-2023 and is owned by Tenable, Inc. or an Affiliate thereof.ALMA_LINUX_ALSA-2021-5227.NASL
HistoryMar 11, 2022 - 12:00 a.m.

AlmaLinux 8 : kernel (ALSA-2021:5227)

2022-03-1100:00:00
This script is Copyright (C) 2022-2023 and is owned by Tenable, Inc. or an Affiliate thereof.
www.tenable.com
96

4.7 Medium

CVSS3

Attack Vector

LOCAL

Attack Complexity

HIGH

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

4.7 Medium

CVSS2

Access Vector

Access Complexity

Authentication

NONE

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

COMPLETE

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

0.0004 Low

EPSS

Percentile

5.2%

The remote AlmaLinux 8 host has packages installed that are affected by a vulnerability as referenced in the ALSA-2021:5227 advisory.

  • A race condition accessing file object in the Linux kernel OverlayFS subsystem was found in the way users do rename in specific way with OverlayFS. A local user could use this flaw to crash the system.
    (CVE-2021-20321)

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 package checks in this plugin were extracted from
# AlmaLinux Security Advisory ALSA-2021:5227.
##

include('deprecated_nasl_level.inc');
include('compat.inc');

if (description)
{
  script_id(158846);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/08/07");

  script_cve_id("CVE-2021-20321");
  script_xref(name:"ALSA", value:"2021:5227");

  script_name(english:"AlmaLinux 8 : kernel (ALSA-2021:5227)");

  script_set_attribute(attribute:"synopsis", value:
"The remote AlmaLinux host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"The remote AlmaLinux 8 host has packages installed that are affected by a vulnerability as referenced in the
ALSA-2021:5227 advisory.

  - A race condition accessing file object in the Linux kernel OverlayFS subsystem was found in the way users
    do rename in specific way with OverlayFS. A local user could use this flaw to crash the system.
    (CVE-2021-20321)

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://errata.almalinux.org/8/ALSA-2021-5227.html");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:M/Au:N/C:N/I:N/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-20321");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"vuln_publication_date", value:"2021/10/28");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/12/21");
  script_set_attribute(attribute:"plugin_publication_date", value:"2022/03/11");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:bpftool");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:kernel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:kernel-abi-stablelists");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:kernel-core");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:kernel-cross-headers");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:kernel-debug");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:kernel-debug-core");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:kernel-debug-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:kernel-debug-modules");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:kernel-debug-modules-extra");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:kernel-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:kernel-headers");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:kernel-modules");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:kernel-modules-extra");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:kernel-tools");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:kernel-tools-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:kernel-tools-libs-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:perf");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:python3-perf");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:alma:linux:8");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Alma 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("ssh_get_info.nasl", "linux_alt_patch_detect.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/AlmaLinux/release", "Host/AlmaLinux/rpm-list", "Host/cpu");

  exit(0);
}


include('rpm.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/AlmaLinux/release');
if (isnull(os_release) || 'AlmaLinux' >!< os_release) audit(AUDIT_OS_NOT, 'AlmaLinux');
var os_ver = pregmatch(pattern: "AlmaLinux release ([0-9]+(\.[0-9]+)?)", string:os_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'AlmaLinux');
os_ver = os_ver[1];
if (! preg(pattern:"^8([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, 'AlmaLinux 8.x', 'AlmaLinux ' + os_ver);

if (!get_kb_item('Host/AlmaLinux/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$" && 's390' >!< cpu && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'AlmaLinux', cpu);

if (get_one_kb_item('Host/ksplice/kernel-cves'))
{
  rm_kb_item(name:'Host/uptrack-uname-r');
  var cve_list = make_list('CVE-2021-20321');
  if (ksplice_cves_check(cve_list))
  {
    audit(AUDIT_PATCH_INSTALLED, 'KSplice hotfix for ALSA-2021:5227');
  }
  else
  {
    __rpm_report = ksplice_reporting_text();
  }
}
var pkgs = [
    {'reference':'bpftool-4.18.0-348.7.1.el8_5', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'bpftool-4.18.0-348.7.1.el8_5', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-4.18.0-348.7.1.el8_5', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-4.18.0-348.7.1.el8_5', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-abi-stablelists-4.18.0-348.7.1.el8_5', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-core-4.18.0-348.7.1.el8_5', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-core-4.18.0-348.7.1.el8_5', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-cross-headers-4.18.0-348.7.1.el8_5', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-cross-headers-4.18.0-348.7.1.el8_5', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-debug-4.18.0-348.7.1.el8_5', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-debug-4.18.0-348.7.1.el8_5', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-debug-core-4.18.0-348.7.1.el8_5', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-debug-core-4.18.0-348.7.1.el8_5', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-debug-devel-4.18.0-348.7.1.el8_5', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-debug-devel-4.18.0-348.7.1.el8_5', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-debug-modules-4.18.0-348.7.1.el8_5', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-debug-modules-4.18.0-348.7.1.el8_5', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-debug-modules-extra-4.18.0-348.7.1.el8_5', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-debug-modules-extra-4.18.0-348.7.1.el8_5', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-devel-4.18.0-348.7.1.el8_5', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-devel-4.18.0-348.7.1.el8_5', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-modules-4.18.0-348.7.1.el8_5', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-modules-4.18.0-348.7.1.el8_5', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-modules-extra-4.18.0-348.7.1.el8_5', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-modules-extra-4.18.0-348.7.1.el8_5', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-tools-4.18.0-348.7.1.el8_5', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-tools-4.18.0-348.7.1.el8_5', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-tools-libs-4.18.0-348.7.1.el8_5', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-tools-libs-4.18.0-348.7.1.el8_5', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-tools-libs-devel-4.18.0-348.7.1.el8_5', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-tools-libs-devel-4.18.0-348.7.1.el8_5', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'perf-4.18.0-348.7.1.el8_5', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'perf-4.18.0-348.7.1.el8_5', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'python3-perf-4.18.0-348.7.1.el8_5', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'python3-perf-4.18.0-348.7.1.el8_5', 'cpu':'x86_64', 'release':'8', '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 = 'Alma-' + 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_WARNING,
      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, 'bpftool / kernel / kernel-abi-stablelists / kernel-core / etc');
}
VendorProductVersionCPE
almalinuxbpftoolp-cpe:/a:alma:linux:bpftool
almalinuxkernelp-cpe:/a:alma:linux:kernel
almalinuxkernel-abi-stablelistsp-cpe:/a:alma:linux:kernel-abi-stablelists
almalinuxkernel-corep-cpe:/a:alma:linux:kernel-core
almalinuxkernel-cross-headersp-cpe:/a:alma:linux:kernel-cross-headers
almalinuxkernel-debugp-cpe:/a:alma:linux:kernel-debug
almalinuxkernel-debug-corep-cpe:/a:alma:linux:kernel-debug-core
almalinuxkernel-debug-develp-cpe:/a:alma:linux:kernel-debug-devel
almalinuxkernel-debug-modulesp-cpe:/a:alma:linux:kernel-debug-modules
almalinuxkernel-debug-modules-extrap-cpe:/a:alma:linux:kernel-debug-modules-extra
Rows per page:
1-10 of 201

4.7 Medium

CVSS3

Attack Vector

LOCAL

Attack Complexity

HIGH

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

4.7 Medium

CVSS2

Access Vector

Access Complexity

Authentication

NONE

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

COMPLETE

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

0.0004 Low

EPSS

Percentile

5.2%