Vulnerabilities > CVE-2020-8163 - Code Injection vulnerability in multiple products

047910
CVSS 6.5 - MEDIUM
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
SINGLE
Confidentiality impact
PARTIAL
Integrity impact
PARTIAL
Availability impact
PARTIAL
network
low complexity
rubyonrails
debian
CWE-94
nessus

Summary

The is a code injection vulnerability in versions of Rails prior to 5.0.1 that wouldallow an attacker who controlled the `locals` argument of a `render` call to perform a RCE.

Vulnerable Configurations

Part Description Count
Application
Rubyonrails
327
OS
Debian
1

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Leverage Executable Code in Non-Executable Files
    An attack of this type exploits a system's trust in configuration and resource files, when the executable loads the resource (such as an image file or configuration file) the attacker has modified the file to either execute malicious code directly or manipulate the target process (e.g. application server) to execute based on the malicious configuration parameters. Since systems are increasingly interrelated mashing up resources from local and remote sources the possibility of this attack occurring is high. The attack can be directed at a client system, such as causing buffer overrun through loading seemingly benign image files, as in Microsoft Security Bulletin MS04-028 where specially crafted JPEG files could cause a buffer overrun once loaded into the browser. Another example targets clients reading pdf files. In this case the attacker simply appends javascript to the end of a legitimate url for a pdf (http://www.gnucitizen.org/blog/danger-danger-danger/) http://path/to/pdf/file.pdf#whatever_name_you_want=javascript:your_code_here The client assumes that they are reading a pdf, but the attacker has modified the resource and loaded executable javascript into the client's browser process. The attack can also target server processes. The attacker edits the resource or configuration file, for example a web.xml file used to configure security permissions for a J2EE app server, adding role name "public" grants all users with the public role the ability to use the administration functionality. The server trusts its configuration file to be correct, but when they are manipulated, the attacker gains full control.
  • Manipulating User-Controlled Variables
    This attack targets user controlled variables (DEBUG=1, PHP Globals, and So Forth). An attacker can override environment variables leveraging user-supplied, untrusted query variables directly used on the application server without any data sanitization. In extreme cases, the attacker can change variables controlling the business logic of the application. For instance, in languages like PHP, a number of poorly set default configurations may allow the user to override variables.

Nessus

NASL familyFreeBSD Local Security Checks
NASL idFREEBSD_PKG_CE6DB19B976E11EA93C408002728F74C.NASL
descriptionRuby on Rails blog : Due to an unfortunate oversight, Rails 4.2.11.2 has a missing constant error. To address this Rails 4.2.11.3 has been released. The original announcement for CVE-2020-8163 has a follow-up message with an updated patch if you
last seen2020-05-19
modified2020-05-18
plugin id136689
published2020-05-18
reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/136689
titleFreeBSD : Rails -- remote code execution vulnerability (ce6db19b-976e-11ea-93c4-08002728f74c)
code
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from the FreeBSD VuXML database :
#
# Copyright 2003-2020 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(136689);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/07/08");

  script_cve_id("CVE-2020-8163");

  script_name(english:"FreeBSD : Rails -- remote code execution vulnerability (ce6db19b-976e-11ea-93c4-08002728f74c)");
  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:
"Ruby on Rails blog :

Due to an unfortunate oversight, Rails 4.2.11.2 has a missing constant
error. To address this Rails 4.2.11.3 has been released.

The original announcement for CVE-2020-8163 has a follow-up message
with an updated patch if you're unable to use the gems."
  );
  # https://weblog.rubyonrails.org/2020/5/16/rails-4-2-11-3-has-been-released/
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?32a9a2fc"
  );
  # https://groups.google.com/forum/#!topic/rubyonrails-security/hWuKcHyoKh0
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?00df6893"
  );
  # https://vuxml.freebsd.org/freebsd/ce6db19b-976e-11ea-93c4-08002728f74c.html
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?5a540702"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected package.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:P/I:P/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:L/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-8163");
  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:rubygem-actionview4");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:freebsd:freebsd");

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/05/15");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/05/16");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/05/18");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2020 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:"rubygem-actionview4<4.2.11.2")) 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");