Amazon Linux 2 : memcached (ALAS-2018-964)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux 2 Security Advisory ALAS-2018-964.
#

include("compat.inc");

if (description)
{
  script_id(109132);
  script_version("1.4");
  script_cvs_date("Date: 2019/04/05 23:25:05");

  script_cve_id("CVE-2018-1000115");
  script_xref(name:"ALAS", value:"2018-964");

  script_name(english:"Amazon Linux 2 : memcached (ALAS-2018-964)");
  script_summary(english:"Checks rpm output for the updated packages");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote Amazon Linux 2 host is missing a security update."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"It was discovered that the memcached daemon listened on UDP port 11211
by default. An attacker could use memcached for UDP amplification
denial-of-service attacks. The UDP port has been disabled by default,
but can still be enabled.

It was discovered that the memcached connections using UDP transport
protocol can be abused for efficient traffic amplification distributed
denial of service (DDoS) attacks. A remote attacker could send a
malicious UDP request using a spoofed source IP address of a target
system to memcached, causing it to send a significantly larger
response to the target. (CVE-2018-1000115)"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://alas.aws.amazon.com/AL2/ALAS-2018-964.html"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Run 'yum update memcached' to update your system."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P");
  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:N/UI:N/S:U/C:N/I:N/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/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:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:memcached");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:memcached-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:memcached-devel");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux:2");

  script_set_attribute(attribute:"patch_publication_date", value:"2018/03/08");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/04/18");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2018-2019 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 != "2")
{
  if (os_ver == 'A') os_ver = 'AMI';
  audit(AUDIT_OS_NOT, "Amazon Linux 2", "Amazon Linux " + os_ver);
}

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


flag = 0;
if (rpm_check(release:"AL2", cpu:"x86_64", reference:"memcached-1.4.15-10.amzn2.1.1")) flag++;
if (rpm_check(release:"AL2", cpu:"x86_64", reference:"memcached-debuginfo-1.4.15-10.amzn2.1.1")) flag++;
if (rpm_check(release:"AL2", cpu:"x86_64", reference:"memcached-devel-1.4.15-10.amzn2.1.1")) flag++;

if (flag)
{
  if (report_verbosity > 0) security_warning(port:0, extra:rpm_report_get());
  else security_warning(0);
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "memcached / memcached-debuginfo / memcached-devel");
}