Amazon Linux AMI : httpd24 (ALAS-2017-863)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux AMI Security Advisory ALAS-2017-863.
#

include("compat.inc");

if (description)
{
  script_id(102178);
  script_version("3.5");
  script_cvs_date("Date: 2018/04/18 15:09:36");

  script_cve_id("CVE-2016-8743", "CVE-2017-3167", "CVE-2017-3169", "CVE-2017-7659", "CVE-2017-7668", "CVE-2017-7679");
  script_xref(name:"ALAS", value:"2017-863");

  script_name(english:"Amazon Linux AMI : httpd24 (ALAS-2017-863)");
  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:
"ap_find_token() buffer overread :

A buffer over-read flaw was found in the httpd's ap_find_token()
function. A remote attacker could use this flaw to cause httpd child
process to crash via a specially crafted HTTP request. (CVE-2017-7668
)

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)

ap_get_basic_auth_pw() authentication bypass :

It was discovered that the use of httpd's ap_get_basic_auth_pw() API
function outside of the authentication phase could lead to
authentication bypass. A remote attacker could possibly use this flaw
to bypass required authentication if the API was used incorrectly by
one of the modules used by httpd. (CVE-2017-3167)

mod_mime buffer overread :

A buffer over-read flaw was found in the httpd's mod_mime module. A
user permitted to modify httpd's MIME configuration could use this
flaw to cause httpd child process to crash. (CVE-2017-7679)

mod_http2 NULL pointer dereference :

A NULL pointer dereference flaw was found in the mod_http2 module of
httpd. A remote attacker could use this flaw to cause httpd child
process to crash via a specially crafted HTTP/2 request.
(CVE-2017-7659)

mod_ssl NULL pointer dereference :

A NULL pointer dereference flaw was found in the httpd's mod_ssl
module. A remote attacker could use this flaw to cause a httpd child
process to crash if another module used by httpd called a certain API
function during the processing of an HTTPS request. (CVE-2017-3169)"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://alas.aws.amazon.com/ALAS-2017-863.html"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Run 'yum update httpd24' to update your system."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:httpd24");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:httpd24-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:httpd24-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:httpd24-manual");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:httpd24-tools");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:mod24_ldap");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:mod24_proxy_html");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:mod24_session");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:mod24_ssl");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux");

  script_set_attribute(attribute:"patch_publication_date", value:"2017/08/03");
  script_set_attribute(attribute:"plugin_publication_date", value:"2017/08/04");
  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:"httpd24-2.4.27-3.71.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"httpd24-debuginfo-2.4.27-3.71.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"httpd24-devel-2.4.27-3.71.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"httpd24-manual-2.4.27-3.71.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"httpd24-tools-2.4.27-3.71.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"mod24_ldap-2.4.27-3.71.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"mod24_proxy_html-2.4.27-3.71.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"mod24_session-2.4.27-3.71.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"mod24_ssl-2.4.27-3.71.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, "httpd24 / httpd24-debuginfo / httpd24-devel / httpd24-manual / etc");
}