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nessusThis script is Copyright (C) 2021-2023 and is owned by Tenable, Inc. or an Affiliate thereof.FREEBSD_PKG_5FA90EE6BC9E11EBA287E0D55E2A8BF9.NASL
HistoryMay 25, 2021 - 12:00 a.m.

FreeBSD : texproc/expat2 -- billion laugh attack (5fa90ee6-bc9e-11eb-a287-e0d55e2a8bf9)

2021-05-2500:00:00
This script is Copyright (C) 2021-2023 and is owned by Tenable, Inc. or an Affiliate thereof.
www.tenable.com
168

6.9 Medium

AI Score

Confidence

High

Kurt Seifried reports :

So here are the CVE’s for the two big ones, libxml2 and expat. Both are affected by the expansion of internal entities (which can be used to consume resources) and external entities (which can cause a denial of service against other services, be used to port scan, etc.).

A billion laughs attack is a type of denial-of-service attack which is aimed at parsers of XML documents.

#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from the FreeBSD VuXML database :
#
# Copyright 2003-2021 Jacques Vidrine and contributors
#
# Redistribution and use in source (VuXML) and 'compiled' forms (SGML,
# HTML, PDF, PostScript, RTF and so forth) with or without modification,
# are permitted provided that the following conditions are met:
# 1. Redistributions of source code (VuXML) must retain the above
#    copyright notice, this list of conditions and the following
#    disclaimer as the first lines of this file unmodified.
# 2. Redistributions in compiled form (transformed to other DTDs,
#    published online in any format, converted to PDF, PostScript,
#    RTF and other formats) must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer
#    in the documentation and/or other materials provided with the
#    distribution.
# 
# THIS DOCUMENTATION IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
# THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
# OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
# OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
# BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
# WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
# OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS DOCUMENTATION,
# EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#

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

if (description)
{
  script_id(149883);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/12/29");

  script_cve_id("CVE-2013-0340");

  script_name(english:"FreeBSD : texproc/expat2 -- billion laugh attack (5fa90ee6-bc9e-11eb-a287-e0d55e2a8bf9)");

  script_set_attribute(attribute:"synopsis", value:
"The remote FreeBSD host is missing a security-related update.");
  script_set_attribute(attribute:"description", value:
"Kurt Seifried reports :

So here are the CVE's for the two big ones, libxml2 and expat. Both
are affected by the expansion of internal entities (which can be used
to consume resources) and external entities (which can cause a denial
of service against other services, be used to port scan, etc.).

A billion laughs attack is a type of denial-of-service attack which is
aimed at parsers of XML documents.");
  script_set_attribute(attribute:"see_also", value:"https://www.openwall.com/lists/oss-security/2013/02/22/3");
  # https://blog.hartwork.org/posts/cve-2013-0340-billion-laughs-fixed-in-expat-2-4-0/
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?96464edc");
  # https://vuxml.freebsd.org/freebsd/5fa90ee6-bc9e-11eb-a287-e0d55e2a8bf9.html
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?21e30a9d");
  script_set_attribute(attribute:"solution", value:
"Update the affected package.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:P/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:H/I:N/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2013-0340");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2013/02/21");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/05/24");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/05/25");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:freebsd:freebsd:expat");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:freebsd:freebsd");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2021-2023 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/FreeBSD/release", "Host/FreeBSD/pkg_info");

  exit(0);
}


include("audit.inc");
include("freebsd_package.inc");


if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item("Host/FreeBSD/release")) audit(AUDIT_OS_NOT, "FreeBSD");
if (!get_kb_item("Host/FreeBSD/pkg_info")) audit(AUDIT_PACKAGE_LIST_MISSING);


flag = 0;

if (pkg_test(save_report:TRUE, pkg:"expat<2.4.1")) flag++;

if (flag)
{
  if (report_verbosity > 0) security_warning(port:0, extra:pkg_report_get());
  else security_warning(0);
  exit(0);
}
else audit(AUDIT_HOST_NOT, "affected");
VendorProductVersionCPE
freebsdfreebsdexpatp-cpe:/a:freebsd:freebsd:expat
freebsdfreebsdcpe:/o:freebsd:freebsd