FreeBSD : perl -- denial of service via algorithmic complexity attack on hashing routines (68c1f75b-8824-11e2-9996-c48508086173)

2013-03-12T00:00:00
ID FREEBSD_PKG_68C1F75B882411E29996C48508086173.NASL
Type nessus
Reporter Tenable
Modified 2018-11-21T00:00:00

Description

Perl developers report :

In order to prevent an algorithmic complexity attack against its hashing mechanism, perl will sometimes recalculate keys and redistribute the contents of a hash. This mechanism has made perl robust against attacks that have been demonstrated against other systems.

Research by Yves Orton has recently uncovered a flaw in the rehashing code which can result in pathological behavior. This flaw could be exploited to carry out a denial of service attack against code that uses arbitrary user input as hash keys.

Because using user-provided strings as hash keys is a very common operation, we urge users of perl to update their perl executable as soon as possible.

                                        
                                            #
# (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.
#

if (NASL_LEVEL < 3000) exit(0);

include("compat.inc");

if (description)
{
  script_id(65199);
  script_version("1.7");
  script_cvs_date("Date: 2018/11/21 10:46:30");

  script_cve_id("CVE-2013-1667");

  script_name(english:"FreeBSD : perl -- denial of service via algorithmic complexity attack on hashing routines (68c1f75b-8824-11e2-9996-c48508086173)");
  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:
"Perl developers report :

In order to prevent an algorithmic complexity attack against its
hashing mechanism, perl will sometimes recalculate keys and
redistribute the contents of a hash. This mechanism has made perl
robust against attacks that have been demonstrated against other
systems.

Research by Yves Orton has recently uncovered a flaw in the rehashing
code which can result in pathological behavior. This flaw could be
exploited to carry out a denial of service attack against code that
uses arbitrary user input as hash keys.

Because using user-provided strings as hash keys is a very common
operation, we urge users of perl to update their perl executable as
soon as possible."
  );
  # http://www.nntp.perl.org/group/perl.perl5.porters/2013/03/msg199755.html
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?ed817f26"
  );
  # https://vuxml.freebsd.org/freebsd/68c1f75b-8824-11e2-9996-c48508086173.html
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?9ea930fe"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2013/03/04");
  script_set_attribute(attribute:"patch_publication_date", value:"2013/03/10");
  script_set_attribute(attribute:"plugin_publication_date", value:"2013/03/12");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2013-2018 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:"perl<5.12.4_5")) flag++;
if (pkg_test(save_report:TRUE, pkg:"perl>=5.14.0<5.14.2_3")) flag++;
if (pkg_test(save_report:TRUE, pkg:"perl>=5.16.0<5.16.2_1")) flag++;
if (pkg_test(save_report:TRUE, pkg:"perl-threaded<5.12.4_5")) flag++;
if (pkg_test(save_report:TRUE, pkg:"perl-threaded>=5.14.0<5.14.2_3")) flag++;
if (pkg_test(save_report:TRUE, pkg:"perl-threaded>=5.16.0<5.16.2_1")) 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");