Amazon Linux AMI : httpd (ALAS-2017-851)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux AMI Security Advisory ALAS-2017-851.
#

include("compat.inc");

if (description)
{
  script_id(101004);
  script_version("3.4");
  script_cvs_date("Date: 2018/04/18 15:09:36");

  script_cve_id("CVE-2016-8743");
  script_xref(name:"ALAS", value:"2017-851");

  script_name(english:"Amazon Linux AMI : httpd (ALAS-2017-851)");
  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:
"Apache HTTP Request Parsing Whitespace Defects

It was discovered that the HTTP parser in httpd incorrectly allowed
certain characters not permitted by the HTTP protocol specification to
appear unencoded in HTTP request headers. If httpd was used in
conjunction with a proxy or backend server that interpreted those
characters differently, a remote attacker could possibly use this flaw
to inject data into HTTP responses, resulting in proxy cache
poisoning.(CVE-2016-8743)"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://alas.aws.amazon.com/ALAS-2017-851.html"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Run 'yum update httpd' to update your system."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:N");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:httpd");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:httpd-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:httpd-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:httpd-manual");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:httpd-tools");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:mod_ssl");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux");

  script_set_attribute(attribute:"patch_publication_date", value:"2017/06/22");
  script_set_attribute(attribute:"plugin_publication_date", value:"2017/06/23");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2017-2018 Tenable Network Security, Inc.");
  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:"httpd-2.2.32-1.9.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"httpd-debuginfo-2.2.32-1.9.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"httpd-devel-2.2.32-1.9.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"httpd-manual-2.2.32-1.9.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"httpd-tools-2.2.32-1.9.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"mod_ssl-2.2.32-1.9.amzn1")) 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, "httpd / httpd-debuginfo / httpd-devel / httpd-manual / httpd-tools / etc");
}