Amazon Linux AMI : kernel (ALAS-2021-1480)

##
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux AMI Security Advisory ALAS-2021-1480.
##

include('compat.inc');

if (description)
{
  script_id(146569);
  script_version("1.7");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/05/24");

  script_cve_id(
    "CVE-2020-27825",
    "CVE-2020-28374",
    "CVE-2021-3178",
    "CVE-2021-3347",
    "CVE-2021-3348",
    "CVE-2021-39648",
    "CVE-2023-1390"
  );
  script_xref(name:"ALAS", value:"2021-1480");

  script_name(english:"Amazon Linux AMI : kernel (ALAS-2021-1480)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Amazon Linux AMI host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"The version of kernel installed on the remote host is prior to 4.14.219-119.340. It is, therefore, affected by multiple
vulnerabilities as referenced in the ALAS-2021-1480 advisory.

    2024-05-23: CVE-2023-1390 was added to this advisory.

    A use-after-free flaw was found in kernel/trace/ring_buffer.c in Linux kernel. There was a race problem in
    trace_open and resize of cpu buffer running parallely on different cpus, may cause a denial of service
    problem (DOS). This flaw could even allow a local attacker with special user  privilege to a kernel
    information leak threat. (CVE-2020-27825)

    A flaw was found in the Linux kernel's implementation of the Linux SCSI target host, where an
    authenticated attacker could write to any block on the exported SCSI device backing store. This flaw
    allows an authenticated attacker to send LIO block requests to the Linux system to overwrite data on the
    backing store. The highest threat from this vulnerability is to integrity. In addition, this flaw affects
    the tcmu-runner package, where the affected SCSI command is called. (CVE-2020-28374)

    A flaw leak of the file handle for parent directory in the Linux kernel's NFS3 functionality was found in
    the way user calls READDIRPLUS. A local user could use this flaw to traverse to other parts of the file-
    system than mounted sub-folder. (CVE-2021-3178)

    A flaw was found in the Linux kernel. A use-after-free memory flaw in the Fast Userspace Mutexes
    functionality allowing a local user to crash the system or escalate their privileges on the system. The
    highest threat from this vulnerability is to data confidentiality and integrity as well as system
    availability. (CVE-2021-3347)

    A use after free flaw in the Linux kernel network block device (NBD) subsystem was found in the way user
    calls an ioctl NBD_SET_SOCK at a certain point during device setup. (CVE-2021-3348)

    In gadget_dev_desc_UDC_show of configfs.c, there is a possible disclosure of kernel heap memory due to a
    race condition. This could lead to local information disclosure with System execution privileges needed.
    User interaction is not needed for exploitation.Product: AndroidVersions: Android kernelAndroid ID:
    A-160822094References: Upstream kernel (CVE-2021-39648)

    A remote denial of service vulnerability was found in the Linux kernel's TIPC kernel module. The while
    loop in tipc_link_xmit() hits an unknown state while attempting to parse SKBs, which are not in the queue.
    Sending two small UDP packets to a system with a UDP bearer results in the CPU utilization for the system
    to instantly spike to 100%, causing a denial of service condition. (CVE-2023-1390)

Tenable has extracted the preceding description block directly from the tested product security advisory.

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://alas.aws.amazon.com/ALAS-2021-1480.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2020-27825.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2020-28374.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-3178.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-3347.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-3348.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-39648.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2023-1390.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/faqs.html");
  script_set_attribute(attribute:"solution", value:
"Run 'yum update kernel' to update your system.");
  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:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-3347");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2020-28374");

  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:"2020/12/11");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/02/16");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/02/18");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-debuginfo-common-i686");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-debuginfo-common-x86_64");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-headers");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-tools");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-tools-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-tools-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:perf");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:perf-debuginfo");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2021-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("kpatch.nasl", "ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/AmazonLinux/release", "Host/AmazonLinux/rpm-list");

  exit(0);
}

include("rpm.inc");
include("hotfixes.inc");

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);

var alas_release = get_kb_item("Host/AmazonLinux/release");
if (isnull(alas_release) || !strlen(alas_release)) audit(AUDIT_OS_NOT, "Amazon Linux");
var os_ver = pregmatch(pattern: "^AL(A|\d+|-\d+)", string:alas_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Amazon Linux");
os_ver = os_ver[1];
if (os_ver != "A")
{
  if (os_ver == 'A') os_ver = 'AMI';
  audit(AUDIT_OS_NOT, "Amazon Linux AMI", "Amazon Linux " + os_ver);
}

if (!get_kb_item("Host/AmazonLinux/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);

if (get_one_kb_item("Host/kpatch/kernel-cves"))
{
  set_hotfix_type("kpatch");
  var cve_list = make_list("CVE-2020-27825", "CVE-2020-28374", "CVE-2021-3178", "CVE-2021-3347", "CVE-2021-3348", "CVE-2021-39648", "CVE-2023-1390");
  if (hotfix_cves_check(cve_list))
  {
    audit(AUDIT_PATCH_INSTALLED, "kpatch hotfix for ALAS-2021-1480");
  }
  else
  {
    __rpm_report = hotfix_reporting_text();
  }
}
var pkgs = [
    {'reference':'kernel-4.14.219-119.340.amzn1', 'cpu':'i686', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-4.14.219-119.340.amzn1', 'cpu':'x86_64', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-debuginfo-4.14.219-119.340.amzn1', 'cpu':'i686', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-debuginfo-4.14.219-119.340.amzn1', 'cpu':'x86_64', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-debuginfo-common-i686-4.14.219-119.340.amzn1', 'cpu':'i686', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-debuginfo-common-x86_64-4.14.219-119.340.amzn1', 'cpu':'x86_64', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-devel-4.14.219-119.340.amzn1', 'cpu':'i686', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-devel-4.14.219-119.340.amzn1', 'cpu':'x86_64', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-headers-4.14.219-119.340.amzn1', 'cpu':'i686', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-headers-4.14.219-119.340.amzn1', 'cpu':'x86_64', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-tools-4.14.219-119.340.amzn1', 'cpu':'i686', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-tools-4.14.219-119.340.amzn1', 'cpu':'x86_64', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-tools-debuginfo-4.14.219-119.340.amzn1', 'cpu':'i686', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-tools-debuginfo-4.14.219-119.340.amzn1', 'cpu':'x86_64', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-tools-devel-4.14.219-119.340.amzn1', 'cpu':'i686', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-tools-devel-4.14.219-119.340.amzn1', 'cpu':'x86_64', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'perf-4.14.219-119.340.amzn1', 'cpu':'i686', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'perf-4.14.219-119.340.amzn1', 'cpu':'x86_64', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'perf-debuginfo-4.14.219-119.340.amzn1', 'cpu':'i686', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'perf-debuginfo-4.14.219-119.340.amzn1', 'cpu':'x86_64', 'release':'ALA', '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 = 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 / kernel-debuginfo / kernel-debuginfo-common-x86_64 / etc");
}