Amazon Linux AMI : kernel (ALAS-2016-757) (Dirty COW)

#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux AMI Security Advisory ALAS-2016-757.
#

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

if (description)
{
  script_id(94182);
  script_version("2.20");
  script_set_attribute(attribute:"plugin_modification_date", value:"2022/03/08");

  script_cve_id("CVE-2016-5195");
  script_xref(name:"ALAS", value:"2016-757");
  script_xref(name:"IAVA", value:"2016-A-0306-S");
  script_xref(name:"CISA-KNOWN-EXPLOITED", value:"2022/03/24");

  script_name(english:"Amazon Linux AMI : kernel (ALAS-2016-757) (Dirty COW)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Amazon Linux AMI host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"A race condition was found in the way the Linux kernel's memory
subsystem handled the copy-on-write (COW) breakage of private
read-only memory mappings. An unprivileged local user could use this
flaw to gain write access to otherwise read-only memory mappings and
thus increase their privileges on the system.

(Updated 2016-11-10: This advisory was upgraded to Critical.)");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/ALAS-2016-757.html");
  script_set_attribute(attribute:"solution", value:
"Run 'yum update kernel' to update your system. You will need to reboot
your system in order for the new kernel to be running.");
  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:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"exploit_framework_core", value:"true");
  script_set_attribute(attribute:"exploited_by_malware", value:"true");
  script_set_attribute(attribute:"exploit_framework_canvas", value:"true");
  script_set_attribute(attribute:"canvas_package", value:"CANVAS");
  script_set_attribute(attribute:"in_the_news", value:"true");

  script_set_attribute(attribute:"patch_publication_date", value:"2016/10/20");
  script_set_attribute(attribute:"plugin_publication_date", value:"2016/10/21");

  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-doc");
  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:"stig_severity", value:"I");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2016-2022 and is owned by Tenable, Inc. or an Affiliate thereof.");

  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-4.4.23-31.54.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"kernel-debuginfo-4.4.23-31.54.amzn1")) flag++;
if (rpm_check(release:"ALA", cpu:"i686", reference:"kernel-debuginfo-common-i686-4.4.23-31.54.amzn1")) flag++;
if (rpm_check(release:"ALA", cpu:"x86_64", reference:"kernel-debuginfo-common-x86_64-4.4.23-31.54.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"kernel-devel-4.4.23-31.54.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"kernel-doc-4.4.23-31.54.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"kernel-headers-4.4.23-31.54.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"kernel-tools-4.4.23-31.54.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"kernel-tools-debuginfo-4.4.23-31.54.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"kernel-tools-devel-4.4.23-31.54.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"perf-4.4.23-31.54.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"perf-debuginfo-4.4.23-31.54.amzn1")) flag++;

if (flag)
{
  if (report_verbosity > 0) security_hole(port:0, extra:rpm_report_get());
  else security_hole(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");
}