Vulnerabilities > CVE-2016-4353 - Improper Input Validation vulnerability in multiple products

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
gnupg
canonical
CWE-20
nessus
NVD
Published: 2016-06-13
Updated: 2023-11-07

Summary

ber-decoder.c in Libksba before 1.3.3 does not properly handle decoder stack overflows, which allows remote attackers to cause a denial of service (abort) via crafted BER data.

Vulnerable Configurations

Part Description Count
Application
Gnupg
43
OS
Canonical
2

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Buffer Overflow via Environment Variables
    This attack pattern involves causing a buffer overflow through manipulation of environment variables. Once the attacker finds that they can modify an environment variable, they may try to overflow associated buffers. This attack leverages implicit trust often placed in environment variables.
  • Server Side Include (SSI) Injection
    An attacker can use Server Side Include (SSI) Injection to send code to a web application that then gets executed by the web server. Doing so enables the attacker to achieve similar results to Cross Site Scripting, viz., arbitrary code execution and information disclosure, albeit on a more limited scale, since the SSI directives are nowhere near as powerful as a full-fledged scripting language. Nonetheless, the attacker can conveniently gain access to sensitive files, such as password files, and execute shell commands.
  • Cross Zone Scripting
    An attacker is able to cause a victim to load content into their web-browser that bypasses security zone controls and gain access to increased privileges to execute scripting code or other web objects such as unsigned ActiveX controls or applets. This is a privilege elevation attack targeted at zone-based web-browser security. In a zone-based model, pages belong to one of a set of zones corresponding to the level of privilege assigned to that page. Pages in an untrusted zone would have a lesser level of access to the system and/or be restricted in the types of executable content it was allowed to invoke. In a cross-zone scripting attack, a page that should be assigned to a less privileged zone is granted the privileges of a more trusted zone. This can be accomplished by exploiting bugs in the browser, exploiting incorrect configuration in the zone controls, through a cross-site scripting attack that causes the attackers' content to be treated as coming from a more trusted page, or by leveraging some piece of system functionality that is accessible from both the trusted and less trusted zone. This attack differs from "Restful Privilege Escalation" in that the latter correlates to the inadequate securing of RESTful access methods (such as HTTP DELETE) on the server, while cross-zone scripting attacks the concept of security zones as implemented by a browser.
  • Cross Site Scripting through Log Files
    An attacker may leverage a system weakness where logs are susceptible to log injection to insert scripts into the system's logs. If these logs are later viewed by an administrator through a thin administrative interface and the log data is not properly HTML encoded before being written to the page, the attackers' scripts stored in the log will be executed in the administrative interface with potentially serious consequences. This attack pattern is really a combination of two other attack patterns: log injection and stored cross site scripting.
  • Command Line Execution through SQL Injection
    An attacker uses standard SQL injection methods to inject data into the command line for execution. This could be done directly through misuse of directives such as MSSQL_xp_cmdshell or indirectly through injection of data into the database that would be interpreted as shell commands. Sometime later, an unscrupulous backend application (or could be part of the functionality of the same application) fetches the injected data stored in the database and uses this data as command line arguments without performing proper validation. The malicious data escapes that data plane by spawning new commands to be executed on the host.

Nessus

  • NASL familyUbuntu Local Security Checks
    NASL idUBUNTU_USN-2982-1.NASL
    descriptionHanno Bock discovered that Libksba incorrectly handled decoding certain BER data. An attacker could use this issue to cause Libksba to crash, resulting in a denial of service. This issue only applied to Ubunt 12.04 LTS and Ubuntu 14.04 LTS. (CVE-2016-4353) Hanno Bock discovered that Libksba incorrectly handled decoding certain BER data. An attacker could use this issue to cause Libksba to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only applied to Ubunt 12.04 LTS and Ubuntu 14.04 LTS. (CVE-2016-4354, CVE-2016-4355) Hanno Bock discovered that Libksba incorrectly handled incorrect utf-8 strings when decoding certain DN data. An attacker could use this issue to cause Libksba to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only applied to Ubunt 12.04 LTS and Ubuntu 14.04 LTS. (CVE-2016-4356) Pascal Cuoq discovered that Libksba incorrectly handled incorrect utf-8 strings when decoding certain DN data. An attacker could use this issue to cause Libksba to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2016-4574) Pascal Cuoq discovered that Libksba incorrectly handled decoding certain data. An attacker could use this issue to cause Libksba to crash, resulting in a denial of service. (CVE-2016-4579). Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen2020-06-01
    modified2020-06-02
    plugin id91220
    published2016-05-18
    reporterUbuntu Security Notice (C) 2016-2019 Canonical, Inc. / NASL script (C) 2016-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/91220
    titleUbuntu 12.04 LTS / 14.04 LTS / 15.10 / 16.04 LTS : libksba vulnerabilities (USN-2982-1)
    code
    #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-2982-1. The text 
# itself is copyright (C) Canonical, Inc. See 
# <http://www.ubuntu.com/usn/>. Ubuntu(R) is a registered 
# trademark of Canonical, Inc.
#

include("compat.inc");

if (description)
{
  script_id(91220);
  script_version("2.11");
  script_cvs_date("Date: 2019/09/18 12:31:45");

  script_cve_id("CVE-2016-4353", "CVE-2016-4354", "CVE-2016-4355", "CVE-2016-4356", "CVE-2016-4574", "CVE-2016-4579");
  script_xref(name:"USN", value:"2982-1");

  script_name(english:"Ubuntu 12.04 LTS / 14.04 LTS / 15.10 / 16.04 LTS : libksba vulnerabilities (USN-2982-1)");
  script_summary(english:"Checks dpkg output for updated package.");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote Ubuntu host is missing a security-related patch."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"Hanno Bock discovered that Libksba incorrectly handled decoding
certain BER data. An attacker could use this issue to cause Libksba to
crash, resulting in a denial of service. This issue only applied to
Ubunt 12.04 LTS and Ubuntu 14.04 LTS. (CVE-2016-4353)

Hanno Bock discovered that Libksba incorrectly handled decoding
certain BER data. An attacker could use this issue to cause Libksba to
crash, resulting in a denial of service, or possibly execute arbitrary
code. This issue only applied to Ubunt 12.04 LTS and Ubuntu 14.04 LTS.
(CVE-2016-4354, CVE-2016-4355)

Hanno Bock discovered that Libksba incorrectly handled incorrect
utf-8 strings when decoding certain DN data. An attacker could use
this issue to cause Libksba to crash, resulting in a denial of
service, or possibly execute arbitrary code. This issue only applied
to Ubunt 12.04 LTS and Ubuntu 14.04 LTS. (CVE-2016-4356)

Pascal Cuoq discovered that Libksba incorrectly handled incorrect
utf-8 strings when decoding certain DN data. An attacker could use
this issue to cause Libksba to crash, resulting in a denial of
service, or possibly execute arbitrary code. (CVE-2016-4574)

Pascal Cuoq discovered that Libksba incorrectly handled decoding
certain data. An attacker could use this issue to cause Libksba to
crash, resulting in a denial of service. (CVE-2016-4579).

Note that Tenable Network Security has extracted the preceding
description block directly from the Ubuntu security advisory. Tenable
has attempted to automatically clean and format it as much as possible
without introducing additional issues."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://usn.ubuntu.com/2982-1/"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Update the affected libksba8 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:"exploit_available", value:"false");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libksba8");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:12.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:14.04");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:15.10");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:16.04");

  script_set_attribute(attribute:"vuln_publication_date", value:"2016/06/13");
  script_set_attribute(attribute:"patch_publication_date", value:"2016/05/17");
  script_set_attribute(attribute:"plugin_publication_date", value:"2016/05/18");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"Ubuntu Security Notice (C) 2016-2019 Canonical, Inc. / NASL script (C) 2016-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"Ubuntu Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/cpu", "Host/Ubuntu", "Host/Ubuntu/release", "Host/Debian/dpkg-l");

  exit(0);
}


include("audit.inc");
include("ubuntu.inc");
include("misc_func.inc");

if ( ! get_kb_item("Host/local_checks_enabled") ) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item("Host/Ubuntu/release");
if ( isnull(release) ) audit(AUDIT_OS_NOT, "Ubuntu");
release = chomp(release);
if (! preg(pattern:"^(12\.04|14\.04|15\.10|16\.04)$", string:release)) audit(AUDIT_OS_NOT, "Ubuntu 12.04 / 14.04 / 15.10 / 16.04", "Ubuntu " + release);
if ( ! get_kb_item("Host/Debian/dpkg-l") ) audit(AUDIT_PACKAGE_LIST_MISSING);

cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "Ubuntu", cpu);

flag = 0;

if (ubuntu_check(osver:"12.04", pkgname:"libksba8", pkgver:"1.2.0-2ubuntu0.2")) flag++;
if (ubuntu_check(osver:"14.04", pkgname:"libksba8", pkgver:"1.3.0-3ubuntu0.14.04.2")) flag++;
if (ubuntu_check(osver:"15.10", pkgname:"libksba8", pkgver:"1.3.3-1ubuntu0.15.10.1")) flag++;
if (ubuntu_check(osver:"16.04", pkgname:"libksba8", pkgver:"1.3.3-1ubuntu0.16.04.1")) flag++;

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : ubuntu_report_get()
  );
  exit(0);
}
else
{
  tested = ubuntu_pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "libksba8");
}
  • NASL familyFreeBSD Local Security Checks
    NASL idFREEBSD_PKG_A113404810C611E694FA002590263BF5.NASL
    descriptionMartin Prpic, Red Hat Product Security Team, reports : Denial of Service due to stack overflow in src/ber-decoder.c. Integer overflow in the BER decoder src/ber-decoder.c. Integer overflow in the DN decoder src/dn.c.
    last seen2020-06-01
    modified2020-06-02
    plugin id90848
    published2016-05-03
    reporterThis script is Copyright (C) 2016-2018 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/90848
    titleFreeBSD : libksba -- local denial of service vulnerabilities (a1134048-10c6-11e6-94fa-002590263bf5)
    code
    #
# (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("compat.inc");

if (description)
{
  script_id(90848);
  script_version("2.5");
  script_cvs_date("Date: 2018/11/23 12:49:57");

  script_cve_id("CVE-2016-4353", "CVE-2016-4354", "CVE-2016-4355", "CVE-2016-4356");

  script_name(english:"FreeBSD : libksba -- local denial of service vulnerabilities (a1134048-10c6-11e6-94fa-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:
"Martin Prpic, Red Hat Product Security Team, reports :

Denial of Service due to stack overflow in src/ber-decoder.c.

Integer overflow in the BER decoder src/ber-decoder.c.

Integer overflow in the DN decoder src/dn.c."
  );
  # http://git.gnupg.org/cgi-bin/gitweb.cgi?p=libksba.git;a=commit;h=07116a314f4dcd4d96990bbd74db95a03a9f650a
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?c553173e"
  );
  # http://git.gnupg.org/cgi-bin/gitweb.cgi?p=libksba.git;a=commit;h=aea7b6032865740478ca4b706850a5217f1c3887
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?1abb5a4d"
  );
  # http://git.gnupg.org/cgi-bin/gitweb.cgi?p=libksba.git;a=commit;h=243d12fdec66a4360fbb3e307a046b39b5b4ffc3
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?2ff8ecf3"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://security.gentoo.org/glsa/201604-04"
  );
  # http://www.openwall.com/lists/oss-security/2016/04/29/5
  script_set_attribute(
    attribute:"see_also",
    value:"https://www.openwall.com/lists/oss-security/2016/04/29/5"
  );
  # https://vuxml.freebsd.org/freebsd/a1134048-10c6-11e6-94fa-002590263bf5.html
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?600868b5"
  );
  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_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2015/04/08");
  script_set_attribute(attribute:"patch_publication_date", value:"2016/05/03");
  script_set_attribute(attribute:"plugin_publication_date", value:"2016/05/03");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2016-2018 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:"libksba<1.3.3")) 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");

References