FreeBSD : dropbear -- multiple vulnerabilities (bc19dcca-7b13-11e6-b99e-589cfc0654e1)

2016-09-16T00:00:00
ID FREEBSD_PKG_BC19DCCA7B1311E6B99E589CFC0654E1.NASL
Type nessus
Reporter This script is Copyright (C) 2016-2021 and is owned by Tenable, Inc. or an Affiliate thereof.
Modified 2021-01-04T00:00:00

Description

Matt Johnston reports :

If specific usernames including '%' symbols can be created on a system (validated by getpwnam()) then an attacker could run arbitrary code as root when connecting to Dropbear server.

A dbclient user who can control username or host arguments could potentially run arbitrary code as the dbclient user. This could be a problem if scripts or webpages pass untrusted input to the dbclient program.

dropbearconvert import of OpenSSH keys could run arbitrary code as the local dropbearconvert user when parsing malicious key files.

dbclient could run arbitrary code as the local dbclient user if particular -m or -c arguments are provided. This could be an issue where dbclient is used in scripts.

dbclient or dropbear server could expose process memory to the running user if compiled with DEBUG_TRACE and running with -v

                                        
                                            #%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 2003-2018 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('deprecated_nasl_level.inc');
include('compat.inc');

if (description)
{
  script_id(93552);
  script_version("2.5");
  script_set_attribute(attribute:"plugin_modification_date", value:"2021/01/04");

  script_cve_id("CVE-2016-7406", "CVE-2016-7407", "CVE-2016-7408", "CVE-2016-7409");

  script_name(english:"FreeBSD : dropbear -- multiple vulnerabilities (bc19dcca-7b13-11e6-b99e-589cfc0654e1)");
  script_summary(english:"Checks for updated package in pkg_info output");

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

If specific usernames including '%' symbols can be created on a system
(validated by getpwnam()) then an attacker could run arbitrary code as
root when connecting to Dropbear server.

A dbclient user who can control username or host arguments could
potentially run arbitrary code as the dbclient user. This could be a
problem if scripts or webpages pass untrusted input to the dbclient
program.

dropbearconvert import of OpenSSH keys could run arbitrary code as the
local dropbearconvert user when parsing malicious key files.

dbclient could run arbitrary code as the local dbclient user if
particular -m or -c arguments are provided. This could be an issue
where dbclient is used in scripts.

dbclient or dropbear server could expose process memory to the running
user if compiled with DEBUG_TRACE and running with -v"
  );
  # http://www.openwall.com/lists/oss-security/2016/09/15/2
  script_set_attribute(
    attribute:"see_also",
    value:"https://www.openwall.com/lists/oss-security/2016/09/15/2"
  );
  # https://vuxml.freebsd.org/freebsd/bc19dcca-7b13-11e6-b99e-589cfc0654e1.html
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?002ecf86"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected package.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C");
  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:freebsd:freebsd:dropbear");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:freebsd:freebsd");

  script_set_attribute(attribute:"vuln_publication_date", value:"2016/07/12");
  script_set_attribute(attribute:"patch_publication_date", value:"2016/09/15");
  script_set_attribute(attribute:"plugin_publication_date", value:"2016/09/16");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2016-2021 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:"dropbear<2016.74")) flag++;

if (flag)
{
  if (report_verbosity > 0) security_hole(port:0, extra:pkg_report_get());
  else security_hole(0);
  exit(0);
}
else audit(AUDIT_HOST_NOT, "affected");