Ubuntu 12.04 LTS / 14.04 LTS / 14.10 : libyaml vulnerability (USN-2461-1)

2015-01-13T00:00:00
ID UBUNTU_USN-2461-1.NASL
Type nessus
Reporter Tenable
Modified 2018-08-03T00:00:00

Description

Stanislaw Pitucha and Jonathan Gray discovered that LibYAML did not properly handle wrapped strings. An attacker could create specially crafted YAML data to trigger an assert, causing a denial of service.

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.

                                        
                                            #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-2461-1. 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(80472);
  script_version("1.6");
  script_cvs_date("Date: 2018/08/03 12:21:24");

  script_cve_id("CVE-2014-9130");
  script_bugtraq_id(71349);
  script_xref(name:"USN", value:"2461-1");

  script_name(english:"Ubuntu 12.04 LTS / 14.04 LTS / 14.10 : libyaml vulnerability (USN-2461-1)");
  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:
"Stanislaw Pitucha and Jonathan Gray discovered that LibYAML did not
properly handle wrapped strings. An attacker could create specially
crafted YAML data to trigger an assert, causing a denial of service.

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:"solution", 
    value:"Update the affected libyaml-0-2 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_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:libyaml-0-2");
  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:14.10");

  script_set_attribute(attribute:"patch_publication_date", value:"2015/01/12");
  script_set_attribute(attribute:"plugin_publication_date", value:"2015/01/13");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"Ubuntu Security Notice (C) 2015-2018 Canonical, Inc. / NASL script (C) 2015-2016 Tenable Network Security, Inc.");
  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 (! ereg(pattern:"^(12\.04|14\.04|14\.10)$", string:release)) audit(AUDIT_OS_NOT, "Ubuntu 12.04 / 14.04 / 14.10", "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:"libyaml-0-2", pkgver:"0.1.4-2ubuntu0.12.04.4")) flag++;
if (ubuntu_check(osver:"14.04", pkgname:"libyaml-0-2", pkgver:"0.1.4-3ubuntu3.1")) flag++;
if (ubuntu_check(osver:"14.10", pkgname:"libyaml-0-2", pkgver:"0.1.6-1ubuntu0.1")) 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, "libyaml-0-2");
}