FreeBSD : go -- information disclosure vulnerability (6809c6db-bdeb-11e5-b5fe-002590263bf5)

2016-01-19T00:00:00
ID FREEBSD_PKG_6809C6DBBDEB11E5B5FE002590263BF5.NASL
Type nessus
Reporter Tenable
Modified 2016-10-19T00:00:00

Description

Jason Buberel reports :

A security-related issue has been reported in Go's math/big package. The issue was introduced in Go 1.5. We recommend that all users upgrade to Go 1.5.3, which fixes the issue. Go programs must be recompiled with Go 1.5.3 in order to receive the fix.

The Go team would like to thank Nick Craig-Wood for identifying the issue.

This issue can affect RSA computations in crypto/rsa, which is used by crypto/tls. TLS servers on 32-bit systems could plausibly leak their RSA private key due to this issue. Other protocol implementations that create many RSA signatures could also be impacted in the same way.

Specifically, incorrect results in one part of the RSA Chinese Remainder computation can cause the result to be incorrect in such a way that it leaks one of the primes. While RSA blinding should prevent an attacker from crafting specific inputs that trigger the bug, on 32-bit systems the bug can be expected to occur at random around one in 2^26 times. Thus collecting around 64 million signatures (of known data) from an affected server should be enough to extract the private key used.

On 64-bit systems, the frequency of the bug is so low (less than one in 2^50) that it would be very difficult to exploit. Nonetheless, everyone is strongly encouraged to upgrade.

                                        
                                            #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from the FreeBSD VuXML database :
#
# Copyright 2003-2016 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(87983);
  script_version("$Revision: 2.3 $");
  script_cvs_date("$Date: 2016/10/19 14:02:54 $");

  script_cve_id("CVE-2015-8618");

  script_name(english:"FreeBSD : go -- information disclosure vulnerability (6809c6db-bdeb-11e5-b5fe-002590263bf5)");
  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:
"Jason Buberel reports :

A security-related issue has been reported in Go's math/big package.
The issue was introduced in Go 1.5. We recommend that all users
upgrade to Go 1.5.3, which fixes the issue. Go programs must be
recompiled with Go 1.5.3 in order to receive the fix.

The Go team would like to thank Nick Craig-Wood for identifying the
issue.

This issue can affect RSA computations in crypto/rsa, which is used by
crypto/tls. TLS servers on 32-bit systems could plausibly leak their
RSA private key due to this issue. Other protocol implementations that
create many RSA signatures could also be impacted in the same way.

Specifically, incorrect results in one part of the RSA Chinese
Remainder computation can cause the result to be incorrect in such a
way that it leaks one of the primes. While RSA blinding should prevent
an attacker from crafting specific inputs that trigger the bug, on
32-bit systems the bug can be expected to occur at random around one
in 2^26 times. Thus collecting around 64 million signatures (of known
data) from an affected server should be enough to extract the private
key used.

On 64-bit systems, the frequency of the bug is so low (less than one
in 2^50) that it would be very difficult to exploit. Nonetheless,
everyone is strongly encouraged to upgrade."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.openwall.com/lists/oss-security/2016/01/13/7"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://go-review.googlesource.com/#/c/17672/"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://go-review.googlesource.com/#/c/18491/"
  );
  # http://www.freebsd.org/ports/portaudit/6809c6db-bdeb-11e5-b5fe-002590263bf5.html
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?8e7563d3"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected package.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2016/01/13");
  script_set_attribute(attribute:"patch_publication_date", value:"2016/01/18");
  script_set_attribute(attribute:"plugin_publication_date", value:"2016/01/19");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2016 Tenable Network Security, Inc.");
  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:"go>=1.5,1<1.5.3,1")) 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");