The OpenSSL project reports :
During key agreement in a TLS handshake using a DH(E) based ciphersuite a malicious server can send a very large prime value to the client. This will cause the client to spend an unreasonably long period of time generating a key for this prime resulting in a hang until the client has finished. This could be exploited in a Denial Of Service attack.
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from the FreeBSD VuXML database :
#
# Copyright 2003-2018 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("compat.inc");
if (description)
{
script_id(110504);
script_version("1.6");
script_cvs_date("Date: 2018/11/10 11:49:47");
script_cve_id("CVE-2018-0732");
script_name(english:"FreeBSD : OpenSSL -- Client DoS due to large DH parameter (c82ecac5-6e3f-11e8-8777-b499baebfeaf)");
script_summary(english:"Checks for updated packages in pkg_info output");
script_set_attribute(
attribute:"synopsis",
value:
"The remote FreeBSD host is missing one or more security-related
updates."
);
script_set_attribute(
attribute:"description",
value:
"The OpenSSL project reports :
During key agreement in a TLS handshake using a DH(E) based
ciphersuite a malicious server can send a very large prime value to
the client. This will cause the client to spend an unreasonably long
period of time generating a key for this prime resulting in a hang
until the client has finished. This could be exploited in a Denial Of
Service attack."
);
script_set_attribute(
attribute:"see_also",
value:"https://www.openssl.org/news/secadv/20180612.txt"
);
# https://vuxml.freebsd.org/freebsd/c82ecac5-6e3f-11e8-8777-b499baebfeaf.html
script_set_attribute(
attribute:"see_also",
value:"http://www.nessus.org/u?1630b29b"
);
script_set_attribute(attribute:"solution", value:"Update the affected packages.");
script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P");
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_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:freebsd:freebsd:libressl");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:freebsd:freebsd:libressl-devel");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:freebsd:freebsd:openssl");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:freebsd:freebsd:openssl-devel");
script_set_attribute(attribute:"cpe", value:"cpe:/o:freebsd:freebsd");
script_set_attribute(attribute:"vuln_publication_date", value:"2018/06/12");
script_set_attribute(attribute:"patch_publication_date", value:"2018/06/12");
script_set_attribute(attribute:"plugin_publication_date", value:"2018/06/13");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_copyright(english:"This script is Copyright (C) 2018 and is owned by Tenable, Inc. or an Affiliate thereof.");
script_family(english:"FreeBSD Local Security Checks");
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:"libressl<2.6.5")) flag++;
if (pkg_test(save_report:TRUE, pkg:"libressl>=2.7.0<2.7.4")) flag++;
if (pkg_test(save_report:TRUE, pkg:"libressl-devel<2.6.5")) flag++;
if (pkg_test(save_report:TRUE, pkg:"libressl-devel>=2.7.0<2.7.4")) flag++;
if (pkg_test(save_report:TRUE, pkg:"openssl<1.0.2o_4,1")) flag++;
if (pkg_test(save_report:TRUE, pkg:"openssl-devel<1.1.0h_2")) 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");