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nessusThis script is Copyright (C) 2021-2022 and is owned by Tenable, Inc. or an Affiliate thereof.ORACLEVM_OVMSA-2021-0023.NASL
HistoryJul 23, 2021 - 12:00 a.m.

OracleVM 3.4 : kernel-uek (OVMSA-2021-0023)

2021-07-2300:00:00
This script is Copyright (C) 2021-2022 and is owned by Tenable, Inc. or an Affiliate thereof.
www.tenable.com
80

The remote OracleVM system is missing necessary patches to address security updates:

  • fs/seq_file.c in the Linux kernel 3.16 through 5.13.x before 5.13.4 does not properly restrict seq buffer allocations, leading to an integer overflow, an Out-of-bounds Write, and escalation to root by an unprivileged user, aka CID-8cae8cd89f05. (CVE-2021-33909)

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, Inc.
#
# The package checks in this plugin were
# extracted from OracleVM Security Advisory OVMSA-2021-0023.
##

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

if (description)
{
  script_id(152045);
  script_version("1.6");
  script_set_attribute(attribute:"plugin_modification_date", value:"2022/03/31");

  script_cve_id("CVE-2021-33909");

  script_name(english:"OracleVM 3.4 : kernel-uek (OVMSA-2021-0023)");

  script_set_attribute(attribute:"synopsis", value:
"The remote OracleVM host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The remote OracleVM system is missing necessary patches to address security updates:

  - fs/seq_file.c in the Linux kernel 3.16 through 5.13.x before 5.13.4 does not properly restrict seq buffer
    allocations, leading to an integer overflow, an Out-of-bounds Write, and escalation to root by an
    unprivileged user, aka CID-8cae8cd89f05. (CVE-2021-33909)

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/cve/CVE-2021-33909.html");
  script_set_attribute(attribute:"see_also", value:"https://linux.oracle.com/errata/OVMSA-2021-0023.html");
  script_set_attribute(attribute:"solution", value:
"Update the affected kernel-uek / kernel-uek-firmware 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:H/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:H/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-33909");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"exploited_by_malware", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2021/07/20");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/07/22");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/07/23");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:vm:kernel-uek");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:vm:kernel-uek-firmware");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:oracle:vm_server:3.4");
  script_set_attribute(attribute:"stig_severity", value:"II");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"OracleVM 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/OracleVM/release", "Host/OracleVM/rpm-list");

  exit(0);
}
include('ksplice.inc');
include('rpm.inc');

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var release = get_kb_item("Host/OracleVM/release");
if (isnull(release) || "OVS" >!< release) audit(AUDIT_OS_NOT, "OracleVM");
if (! preg(pattern:"^OVS" + "3\.4" + "(\.[0-9]|$)", string:release)) audit(AUDIT_OS_NOT, "OracleVM 3.4", "OracleVM " + release);
if (!get_kb_item("Host/OracleVM/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$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "OracleVM", cpu);
if ("x86_64" >!< cpu) audit(AUDIT_ARCH_NOT, "x86_64", 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 = ['4.1.12-124.52.5.el6uek'];
  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 OVMSA-2021-0023');
    }
  }
  __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 = '4.1';
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-4.1.12-124.52.5.el6uek', 'cpu':'x86_64', 'release':'3.4', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-4.1.12'},
    {'reference':'kernel-uek-firmware-4.1.12-124.52.5.el6uek', 'cpu':'x86_64', 'release':'3.4', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-firmware-4.1.12'}
];

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 = 'OVS' + 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_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-firmware');
}
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