Vulnerabilities > CVE-2020-7663

047910
CVSS 7.5 - HIGH
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
NONE
Integrity impact
NONE
Availability impact
HIGH
network
low complexity
websocket-extensions-project
debian
canonical
nessus

Summary

websocket-extensions ruby module prior to 0.1.5 allows Denial of Service (DoS) via Regex Backtracking. The extension parser may take quadratic time when parsing a header containing an unclosed string parameter value whose content is a repeating two-byte sequence of a backslash and some other character. This could be abused by an attacker to conduct Regex Denial Of Service (ReDoS) on a single-threaded server by providing a malicious payload with the Sec-WebSocket-Extensions header.

Nessus

NASL familyFreeBSD Local Security Checks
NASL idFREEBSD_PKG_CA8327F7A5A511EAA86008002728F74C.NASL
descriptionChangelog : Remove a ReDoS vulnerability in the header parser (CVE-2020-7663)
last seen2020-06-10
modified2020-06-04
plugin id137127
published2020-06-04
reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/137127
titleFreeBSD : websocket-extensions -- ReDoS vulnerability (ca8327f7-a5a5-11ea-a860-08002728f74c)
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(137127);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/06/09");

  script_cve_id("CVE-2020-7663");

  script_name(english:"FreeBSD : websocket-extensions -- ReDoS vulnerability (ca8327f7-a5a5-11ea-a860-08002728f74c)");
  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:
"Changelog :

Remove a ReDoS vulnerability in the header parser (CVE-2020-7663)"
  );
  # https://github.com/faye/websocket-extensions-ruby/blob/master/CHANGELOG.md
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?6b4c4fe0"
  );
  # https://github.com/faye/websocket-extensions-ruby/commit/aa156a439da681361ed6f53f1a8131892418838b
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?70c5e9ef"
  );
  # https://vuxml.freebsd.org/freebsd/ca8327f7-a5a5-11ea-a860-08002728f74c.html
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?40536f99"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected package.");
  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:rubygem-websocket-extensions");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:freebsd:freebsd");

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/06/02");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/06/03");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/06/04");
  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-websocket-extensions<0.1.5")) 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");