CentOS 7 : httpd (CESA-2017:0906)

#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Red Hat Security Advisory RHSA-2017:0906 and 
# CentOS Errata and Security Advisory 2017:0906 respectively.
#

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

if (description)
{
  script_id(99379);
  script_version("3.12");
  script_set_attribute(attribute:"plugin_modification_date", value:"2021/01/04");

  script_cve_id("CVE-2016-0736", "CVE-2016-2161", "CVE-2016-4975", "CVE-2016-8743");
  script_xref(name:"RHSA", value:"2017:0906");

  script_name(english:"CentOS 7 : httpd (CESA-2017:0906)");
  script_summary(english:"Checks rpm output for the updated packages");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote CentOS host is missing one or more security updates."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"An update for httpd is now available for Red Hat Enterprise Linux 7.

Red Hat Product Security has rated this update as having a security
impact of Moderate. A Common Vulnerability Scoring System (CVSS) base
score, which gives a detailed severity rating, is available for each
vulnerability from the CVE link(s) in the References section.

The httpd packages provide the Apache HTTP Server, a powerful,
efficient, and extensible web server.

Security Fix(es) :

* It was discovered that the mod_session_crypto module of httpd did
not use any mechanisms to verify integrity of the encrypted session
data stored in the user's browser. A remote attacker could use this
flaw to decrypt and modify session data using a padding oracle attack.
(CVE-2016-0736)

* It was discovered that the mod_auth_digest module of httpd did not
properly check for memory allocation failures. A remote attacker could
use this flaw to cause httpd child processes to repeatedly crash if
the server used HTTP digest authentication. (CVE-2016-2161)

* 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)

Note: The fix for the CVE-2016-8743 issue causes httpd to return '400
Bad Request' error to HTTP clients which do not strictly follow HTTP
protocol specification. A newly introduced configuration directive
'HttpProtocolOptions Unsafe' can be used to re-enable the old less
strict parsing. However, such setting also re-introduces the
CVE-2016-8743 issue.

Bug Fix(es) :

* When waking up child processes during a graceful restart, the httpd
parent process could attempt to open more connections than necessary
if a large number of child processes had been active prior to the
restart. Consequently, a graceful restart could take a long time to
complete. With this update, httpd has been fixed to limit the number
of connections opened during a graceful restart to the number of
active children, and the described problem no longer occurs.
(BZ#1420002)

* Previously, httpd running in a container returned the 500 HTTP
status code (Internal Server Error) when a connection to a WebSocket
server was closed. As a consequence, the httpd server failed to
deliver the correct HTTP status and data to a client. With this
update, httpd correctly handles all proxied requests to the WebSocket
server, and the described problem no longer occurs. (BZ#1429947)

* In a configuration using LDAP authentication with the
mod_authnz_ldap module, the name set using the AuthLDAPBindDN
directive was not correctly used to bind to the LDAP server for all
queries. Consequently, authorization attempts failed. The LDAP modules
have been fixed to ensure the configured name is correctly bound for
LDAP queries, and authorization using LDAP no longer fails.
(BZ#1420047)"
  );
  # https://lists.centos.org/pipermail/centos-announce/2017-April/022380.html
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?e3877b20"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Update the affected httpd packages."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N");
  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:H/I:N/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2016-0736");
  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:centos:centos:httpd");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:httpd-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:httpd-manual");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:httpd-tools");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:mod_ldap");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:mod_proxy_html");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:mod_session");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:mod_ssl");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:centos:centos:7");

  script_set_attribute(attribute:"vuln_publication_date", value:"2017/07/27");
  script_set_attribute(attribute:"patch_publication_date", value:"2017/04/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2017/04/14");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2017-2021 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"CentOS Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/CentOS/release", "Host/CentOS/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/CentOS/release");
if (isnull(release) || "CentOS" >!< release) audit(AUDIT_OS_NOT, "CentOS");
os_ver = pregmatch(pattern: "CentOS(?: Linux)? release ([0-9]+)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "CentOS");
os_ver = os_ver[1];
if (! preg(pattern:"^7([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "CentOS 7.x", "CentOS " + os_ver);

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


cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "CentOS", cpu);


flag = 0;
if (rpm_check(release:"CentOS-7", cpu:"x86_64", reference:"httpd-2.4.6-45.el7.centos.4")) flag++;
if (rpm_check(release:"CentOS-7", cpu:"x86_64", reference:"httpd-devel-2.4.6-45.el7.centos.4")) flag++;
if (rpm_check(release:"CentOS-7", cpu:"x86_64", reference:"httpd-manual-2.4.6-45.el7.centos.4")) flag++;
if (rpm_check(release:"CentOS-7", cpu:"x86_64", reference:"httpd-tools-2.4.6-45.el7.centos.4")) flag++;
if (rpm_check(release:"CentOS-7", cpu:"x86_64", reference:"mod_ldap-2.4.6-45.el7.centos.4")) flag++;
if (rpm_check(release:"CentOS-7", cpu:"x86_64", reference:"mod_proxy_html-2.4.6-45.el7.centos.4")) flag++;
if (rpm_check(release:"CentOS-7", cpu:"x86_64", reference:"mod_session-2.4.6-45.el7.centos.4")) flag++;
if (rpm_check(release:"CentOS-7", cpu:"x86_64", reference:"mod_ssl-2.4.6-45.el7.centos.4")) flag++;


if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "httpd / httpd-devel / httpd-manual / httpd-tools / mod_ldap / etc");
}