FreeBSD : asterisk -- Remote Crash Vulnerability in audio transcoding (7d53d8da-d07a-11e9-8f1a-001999f8d30b)

2019-09-09T00:00:00
ID FREEBSD_PKG_7D53D8DAD07A11E98F1A001999F8D30B.NASL
Type nessus
Reporter This script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof.
Modified 2019-12-31T00:00:00

Description

The Asterisk project reports :

When audio frames are given to the audio transcoding support in Asterisk the number of samples are examined and as part of this a message is output to indicate that no samples are present. A change was done to suppress this message for a particular scenario in which the message was not relevant. This change assumed that information about the origin of a frame will always exist when in reality it may not.

This issue presented itself when an RTP packet containing no audio (and thus no samples) was received. In a particular transcoding scenario this audio frame would get turned into a frame with no origin information. If this new frame was then given to the audio transcoding support a crash would occur as no samples and no origin information would be present. The transcoding scenario requires the genericplc option to be set to enabled (the default) and a transcoding path from the source format into signed linear and then from signed linear into another format.

Note that there may be other scenarios that have not been found which can cause an audio frame with no origin to be given to the audio transcoding support and thus cause a crash.

                                        
                                            #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from the FreeBSD VuXML database :
#
# Copyright 2003-2019 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(128586);
  script_version("1.4");
  script_cvs_date("Date: 2019/12/31");

  script_cve_id("CVE-2019-15639");

  script_name(english:"FreeBSD : asterisk -- Remote Crash Vulnerability in audio transcoding (7d53d8da-d07a-11e9-8f1a-001999f8d30b)");
  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 Asterisk project reports :

When audio frames are given to the audio transcoding support in
Asterisk the number of samples are examined and as part of this a
message is output to indicate that no samples are present. A change
was done to suppress this message for a particular scenario in which
the message was not relevant. This change assumed that information
about the origin of a frame will always exist when in reality it may
not.

This issue presented itself when an RTP packet containing no audio
(and thus no samples) was received. In a particular transcoding
scenario this audio frame would get turned into a frame with no origin
information. If this new frame was then given to the audio transcoding
support a crash would occur as no samples and no origin information
would be present. The transcoding scenario requires the genericplc
option to be set to enabled (the default) and a transcoding path from
the source format into signed linear and then from signed linear into
another format.

Note that there may be other scenarios that have not been found which
can cause an audio frame with no origin to be given to the audio
transcoding support and thus cause a crash."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://downloads.asterisk.org/pub/security/AST-2019-005.html"
  );
  # https://vuxml.freebsd.org/freebsd/7d53d8da-d07a-11e9-8f1a-001999f8d30b.html
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?0c149915"
  );
  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_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  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_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:freebsd:freebsd:asterisk13");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:freebsd:freebsd:asterisk16");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:freebsd:freebsd");

  script_set_attribute(attribute:"vuln_publication_date", value:"2019/08/07");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/09/06");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/09/09");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2019 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:"asterisk13<13.28.1")) flag++;
if (pkg_test(save_report:TRUE, pkg:"asterisk16<16.5.1")) 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");