Lucene search

K
nessusThis script is Copyright (C) 2021-2022 and is owned by Tenable, Inc. or an Affiliate thereof.FEDORA_2021-E49DA8A226.NASL
HistoryMar 24, 2021 - 12:00 a.m.

Fedora 33 : kernel (2021-e49da8a226)

2021-03-2400:00:00
This script is Copyright (C) 2021-2022 and is owned by Tenable, Inc. or an Affiliate thereof.
www.tenable.com
23

CVSS2

3.6

Attack Vector

LOCAL

Attack Complexity

LOW

Authentication

NONE

Confidentiality Impact

PARTIAL

Integrity Impact

NONE

Availability Impact

PARTIAL

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

CVSS3

6

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

HIGH

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

NONE

Availability Impact

HIGH

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

EPSS

0.001

Percentile

17.2%

The remote Fedora 33 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2021-e49da8a226 advisory.

  • An issue was discovered in the Linux kernel before 5.11.8. kernel/bpf/verifier.c performs undesirable out- of-bounds speculation on pointer arithmetic, leading to side-channel attacks that defeat Spectre mitigations and obtain sensitive information from kernel memory, aka CID-f232326f6966. This affects pointer types that do not define a ptr_limit. (CVE-2020-27170)

  • An issue was discovered in the Linux kernel before 5.11.8. kernel/bpf/verifier.c has an off-by-one error (with a resultant integer underflow) affecting out-of-bounds speculation on pointer arithmetic, leading to side-channel attacks that defeat Spectre mitigations and obtain sensitive information from kernel memory, aka CID-10d2bb2e6b1d. (CVE-2020-27171)

  • An issue was discovered in fs/fuse/fuse_i.h in the Linux kernel before 5.11.8. A stall on CPU can occur because a retry loop continually finds the same bad inode, aka CID-775c5033a0d1. (CVE-2021-28950)

Note that Nessus has not tested for this issue but has instead relied only on the application’s self-reported version number.

##
# (C) Tenable Network Security, Inc.
##
# The descriptive text and package checks in this plugin were
# extracted from Fedora Security Advisory FEDORA-2021-e49da8a226
#

include('compat.inc');

if (description)
{
  script_id(148051);
  script_version("1.5");
  script_set_attribute(attribute:"plugin_modification_date", value:"2022/01/21");

  script_cve_id("CVE-2020-27170", "CVE-2020-27171", "CVE-2021-28950");
  script_xref(name:"FEDORA", value:"2021-e49da8a226");

  script_name(english:"Fedora 33 : kernel (2021-e49da8a226)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Fedora host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The remote Fedora 33 host has a package installed that is affected by multiple vulnerabilities as referenced in the
FEDORA-2021-e49da8a226 advisory.

  - An issue was discovered in the Linux kernel before 5.11.8. kernel/bpf/verifier.c performs undesirable out-
    of-bounds speculation on pointer arithmetic, leading to side-channel attacks that defeat Spectre
    mitigations and obtain sensitive information from kernel memory, aka CID-f232326f6966. This affects
    pointer types that do not define a ptr_limit. (CVE-2020-27170)

  - An issue was discovered in the Linux kernel before 5.11.8. kernel/bpf/verifier.c has an off-by-one error
    (with a resultant integer underflow) affecting out-of-bounds speculation on pointer arithmetic, leading to
    side-channel attacks that defeat Spectre mitigations and obtain sensitive information from kernel memory,
    aka CID-10d2bb2e6b1d. (CVE-2020-27171)

  - An issue was discovered in fs/fuse/fuse_i.h in the Linux kernel before 5.11.8. A stall on CPU can occur
    because a retry loop continually finds the same bad inode, aka CID-775c5033a0d1. (CVE-2021-28950)

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://bodhi.fedoraproject.org/updates/FEDORA-2021-e49da8a226");
  script_set_attribute(attribute:"solution", value:
"Update the affected kernel package.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:P/I:N/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:H/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-2020-27171");

  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:"2021/03/20");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/03/22");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/03/24");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:33");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fedoraproject:fedora:kernel");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Fedora Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2021-2022 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/RedHat/release", "Host/RedHat/rpm-list");

  exit(0);
}


include('audit.inc');
include('global_settings.inc');
include('rpm.inc');
include('ksplice.inc');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item('Host/RedHat/release');
if (isnull(release) || 'Fedora' >!< release) audit(AUDIT_OS_NOT, 'Fedora');
os_ver = pregmatch(pattern: "Fedora.*release ([0-9]+)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'Fedora');
os_ver = os_ver[1];
if (! preg(pattern:"^33([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, 'Fedora 33', 'Fedora ' + os_ver);

if (!get_kb_item('Host/RedHat/rpm-list')) audit(AUDIT_PACKAGE_LIST_MISSING);

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, 'Fedora', cpu);

if (get_one_kb_item('Host/ksplice/kernel-cves'))
{
  rm_kb_item(name:'Host/uptrack-uname-r');
  cve_list = make_list('CVE-2020-27170', 'CVE-2020-27171', 'CVE-2021-28950');
  if (ksplice_cves_check(cve_list))
  {
    audit(AUDIT_PATCH_INSTALLED, 'KSplice hotfix for FEDORA-2021-e49da8a226');
  }
  else
  {
    __rpm_report = ksplice_reporting_text();
  }
}

pkgs = [
    {'reference':'kernel-5.11.8-200.fc33', 'release':'FC33', 'rpm_spec_vers_cmp':TRUE}
];

flag = 0;
foreach package_array ( pkgs ) {
  reference = NULL;
  release = NULL;
  sp = NULL;
  cpu = NULL;
  el_string = NULL;
  rpm_spec_vers_cmp = NULL;
  epoch = NULL;
  allowmaj = 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 (reference && release) {
    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_NOTE,
      extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'kernel');
}
VendorProductVersionCPE
fedoraprojectfedora33cpe:/o:fedoraproject:fedora:33
fedoraprojectfedorakernelp-cpe:/a:fedoraproject:fedora:kernel

CVSS2

3.6

Attack Vector

LOCAL

Attack Complexity

LOW

Authentication

NONE

Confidentiality Impact

PARTIAL

Integrity Impact

NONE

Availability Impact

PARTIAL

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

CVSS3

6

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

HIGH

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

NONE

Availability Impact

HIGH

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

EPSS

0.001

Percentile

17.2%