Amazon Linux AMI : kernel (ALAS-2018-1133)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux AMI Security Advisory ALAS-2018-1133.
#

include("compat.inc");

if (description)
{
  script_id(119813);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/03/27");

  script_cve_id("CVE-2018-16862", "CVE-2018-18710", "CVE-2018-19407");
  script_xref(name:"ALAS", value:"2018-1133");

  script_name(english:"Amazon Linux AMI : kernel (ALAS-2018-1133)");
  script_summary(english:"Checks rpm output for the updated packages");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote Amazon Linux AMI host is missing a security update."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"A security flaw was found in the Linux kernel in a way that the
cleancache subsystem clears an inode after the final file truncation
(removal). The new file created with the same inode may contain
leftover pages from cleancache and the old file data instead of the
new one.(CVE-2018-16862)

An issue was discovered in the Linux kernel through 4.19. An
information leak in cdrom_ioctl_select_disc in drivers/cdrom/cdrom.c
could be used by local attackers to read kernel memory because a cast
from unsigned long to int interferes with bounds
checking.(CVE-2018-18710)

A NULL pointer dereference security flaw was found in the Linux kernel
in the vcpu_scan_ioapic() function in arch/x86/kvm/x86.c. This allows
local users with certain privileges to cause a denial of service via a
crafted system call to the KVM subsystem.(CVE-2018-19407)"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://alas.aws.amazon.com/ALAS-2018-1133.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:P/I:N/A:N");
  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:L/UI:N/S:U/C:H/I:N/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2018-18710");
  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");

  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:"vuln_publication_date", value:"2018/10/29");
  script_set_attribute(attribute:"patch_publication_date", value:"2018/12/20");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/12/21");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2018-2020 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"Amazon Linux Local Security Checks");

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

  exit(0);
}


include("audit.inc");
include("global_settings.inc");
include("rpm.inc");


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

release = get_kb_item("Host/AmazonLinux/release");
if (isnull(release) || !strlen(release)) audit(AUDIT_OS_NOT, "Amazon Linux");
os_ver = pregmatch(pattern: "^AL(A|\d)", string: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);


flag = 0;
if (rpm_check(release:"ALA", reference:"kernel-4.14.88-72.73.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"kernel-debuginfo-4.14.88-72.73.amzn1")) flag++;
if (rpm_check(release:"ALA", cpu:"i686", reference:"kernel-debuginfo-common-i686-4.14.88-72.73.amzn1")) flag++;
if (rpm_check(release:"ALA", cpu:"x86_64", reference:"kernel-debuginfo-common-x86_64-4.14.88-72.73.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"kernel-devel-4.14.88-72.73.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"kernel-headers-4.14.88-72.73.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"kernel-tools-4.14.88-72.73.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"kernel-tools-debuginfo-4.14.88-72.73.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"kernel-tools-devel-4.14.88-72.73.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"perf-4.14.88-72.73.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"perf-debuginfo-4.14.88-72.73.amzn1")) flag++;

if (flag)
{
  if (report_verbosity > 0) security_note(port:0, extra:rpm_report_get());
  else security_note(0);
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "kernel / kernel-debuginfo / kernel-debuginfo-common-i686 / etc");
}