Amazon Linux AMI : kernel (ALAS-2021-1539)

#%NASL_MIN_LEVEL 70300
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux AMI Security Advisory ALAS-2021-1539.
##

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

if (description)
{
  script_id(153860);
  script_version("1.7");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/03/19");

  script_cve_id(
    "CVE-2020-16119",
    "CVE-2021-3609",
    "CVE-2021-3655",
    "CVE-2021-3679",
    "CVE-2021-3732",
    "CVE-2021-3753",
    "CVE-2021-22543",
    "CVE-2021-35477",
    "CVE-2021-37576",
    "CVE-2021-38160",
    "CVE-2021-38198",
    "CVE-2021-38204",
    "CVE-2021-38205",
    "CVE-2021-40490",
    "CVE-2022-20141",
    "CVE-2023-28772"
  );
  script_xref(name:"ALAS", value:"2021-1539");

  script_name(english:"Amazon Linux AMI : kernel (ALAS-2021-1539)");

  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 4.14.248-129.473. It is, therefore, affected by multiple
vulnerabilities as referenced in the ALAS-2021-1539 advisory.

  - Use-after-free vulnerability in the Linux kernel exploitable by a local attacker due to reuse of a DCCP
    socket with an attached dccps_hc_tx_ccid object as a listener after being released. Fixed in Ubuntu Linux
    kernel 5.4.0-51.56, 5.3.0-68.63, 4.15.0-121.123, 4.4.0-193.224, 3.13.0.182.191 and 3.2.0-149.196.
    (CVE-2020-16119)

  - An issue was discovered in Linux: KVM through Improper handling of VM_IO|VM_PFNMAP vmas in KVM can bypass
    RO checks and can lead to pages being freed while still accessible by the VMM and guest. This allows users
    with the ability to start and control a VM to read/write random pages of memory and can result in local
    privilege escalation. (CVE-2021-22543)

  - In the Linux kernel through 5.13.7, an unprivileged BPF program can obtain sensitive information from
    kernel memory via a Speculative Store Bypass side-channel attack because a certain preempting store
    operation does not necessarily occur before a store operation that has an attacker-controlled value.
    (CVE-2021-35477)

  - .A flaw was found in the CAN BCM networking protocol in the Linux kernel, where a local attacker can abuse
    a flaw in the CAN subsystem to corrupt memory, crash the system or escalate privileges. This race
    condition in net/can/bcm.c in the Linux kernel allows for local privilege escalation to root.
    (CVE-2021-3609)

  - A vulnerability was found in the Linux kernel in versions prior to v5.14-rc1. Missing size validations on
    inbound SCTP packets may allow the kernel to read uninitialized memory. (CVE-2021-3655)

  - A lack of CPU resource in the Linux kernel tracing module functionality in versions prior to 5.14-rc3 was
    found in the way user uses trace ring buffer in a specific way. Only privileged local users (with
    CAP_SYS_ADMIN capability) could use this flaw to starve the resources causing denial of service.
    (CVE-2021-3679)

  - A flaw was found in the Linux kernel's OverlayFS subsystem in the way the user mounts the TmpFS filesystem
    with OverlayFS. This flaw allows a local user to gain access to hidden files that should not be
    accessible. (CVE-2021-3732)

  - A race problem was seen in the vt_k_ioctl in drivers/tty/vt/vt_ioctl.c in the Linux kernel, which may
    cause an out of bounds read in vt as the write access to vc_mode is not protected by lock-in vt_ioctl
    (KDSETMDE). The highest threat from this vulnerability is to data confidentiality. (CVE-2021-3753)

  - arch/powerpc/kvm/book3s_rtas.c in the Linux kernel through 5.13.5 on the powerpc platform allows KVM guest
    OS users to cause host OS memory corruption via rtas_args.nargs, aka CID-f62f3c20647e. (CVE-2021-37576)

  - In drivers/char/virtio_console.c in the Linux kernel before 5.13.4, data corruption or loss can be
    triggered by an untrusted device that supplies a buf->len value exceeding the buffer size. NOTE: the
    vendor indicates that the cited data corruption is not a vulnerability in any existing use case; the
    length validation was added solely for robustness in the face of anomalous host OS behavior
    (CVE-2021-38160)

  - arch/x86/kvm/mmu/paging_tmpl.h in the Linux kernel before 5.12.11 incorrectly computes the access
    permissions of a shadow page, leading to a missing guest protection page fault. (CVE-2021-38198)

  - drivers/usb/host/max3421-hcd.c in the Linux kernel before 5.13.6 allows physically proximate attackers to
    cause a denial of service (use-after-free and panic) by removing a MAX-3421 USB device in certain
    situations. (CVE-2021-38204)

  - drivers/net/ethernet/xilinx/xilinx_emaclite.c in the Linux kernel before 5.13.3 makes it easier for
    attackers to defeat an ASLR protection mechanism because it prints a kernel pointer (i.e., the real IOMEM
    pointer). (CVE-2021-38205)

  - A race condition was discovered in ext4_write_inline_data_end in fs/ext4/inline.c in the ext4 subsystem in
    the Linux kernel through 5.13.13. (CVE-2021-40490)

  - In ip_check_mc_rcu of igmp.c, there is a possible use after free due to improper locking. This could lead
    to local escalation of privilege when opening and closing inet sockets with no additional execution
    privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android
    kernelAndroid ID: A-112551163References: Upstream kernel (CVE-2022-20141)

  - An issue was discovered in the Linux kernel before 5.13.3. lib/seq_buf.c has a seq_buf_putmem_hex buffer
    overflow. (CVE-2023-28772)

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-2021-1539.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2020-16119.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-3609.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-3655.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-3679.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-3732.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-3753.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-22543.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-35477.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-37576.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-38160.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-38198.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-38204.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-38205.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-40490.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2022-20141.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2023-28772.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:L/AC:L/PR:L/UI:N/S:U/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-2021-38160");

  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:"2020/10/15");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/09/30");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/10/04");

  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("ssh_get_info.nasl", "kpatch.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-2020-16119", "CVE-2021-3609", "CVE-2021-3655", "CVE-2021-3679", "CVE-2021-3732", "CVE-2021-3753", "CVE-2021-22543", "CVE-2021-35477", "CVE-2021-37576", "CVE-2021-38160", "CVE-2021-38198", "CVE-2021-38204", "CVE-2021-38205", "CVE-2021-40490", "CVE-2022-20141", "CVE-2023-28772");
  if (hotfix_cves_check(cve_list))
  {
    audit(AUDIT_PATCH_INSTALLED, "kpatch hotfix for ALAS-2021-1539");
  }
  else
  {
    __rpm_report = hotfix_reporting_text();
  }
}
var pkgs = [
    {'reference':'kernel-4.14.248-129.473.amzn1', 'cpu':'i686', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-4.14.248-129.473.amzn1', 'cpu':'x86_64', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-debuginfo-4.14.248-129.473.amzn1', 'cpu':'i686', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-debuginfo-4.14.248-129.473.amzn1', 'cpu':'x86_64', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-debuginfo-common-i686-4.14.248-129.473.amzn1', 'cpu':'i686', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-debuginfo-common-x86_64-4.14.248-129.473.amzn1', 'cpu':'x86_64', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-devel-4.14.248-129.473.amzn1', 'cpu':'i686', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-devel-4.14.248-129.473.amzn1', 'cpu':'x86_64', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-headers-4.14.248-129.473.amzn1', 'cpu':'i686', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-headers-4.14.248-129.473.amzn1', 'cpu':'x86_64', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-tools-4.14.248-129.473.amzn1', 'cpu':'i686', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-tools-4.14.248-129.473.amzn1', 'cpu':'x86_64', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-tools-debuginfo-4.14.248-129.473.amzn1', 'cpu':'i686', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-tools-debuginfo-4.14.248-129.473.amzn1', 'cpu':'x86_64', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-tools-devel-4.14.248-129.473.amzn1', 'cpu':'i686', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-tools-devel-4.14.248-129.473.amzn1', 'cpu':'x86_64', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'perf-4.14.248-129.473.amzn1', 'cpu':'i686', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'perf-4.14.248-129.473.amzn1', 'cpu':'x86_64', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'perf-debuginfo-4.14.248-129.473.amzn1', 'cpu':'i686', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'perf-debuginfo-4.14.248-129.473.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");
}