Ubuntu 10.04 LTS / 12.04 LTS / 14.04 LTS : bash vulnerabilities (USN-2380-1) (Shellshock)

2014-10-11T00:00:00
ID UBUNTU_USN-2380-1.NASL
Type nessus
Reporter Tenable
Modified 2018-08-03T00:00:00

Description

Michal Zalewski discovered that Bash incorrectly handled parsing certain function definitions. If an attacker were able to create an environment variable containing a function definition with a very specific name, these issues could possibly be used to bypass certain environment restrictions and execute arbitrary code. (CVE-2014-6277, CVE-2014-6278)

Please note that the previous Bash security update, USN-2364-1, includes a hardening measure that prevents these issues from being used in a Shellshock attack.

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-2380-1. 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(78260);
  script_version("1.21");
  script_cvs_date("Date: 2018/08/03 12:21:24");

  script_cve_id("CVE-2014-6277", "CVE-2014-6278");
  script_bugtraq_id(70165, 70166);
  script_xref(name:"USN", value:"2380-1");
  script_xref(name:"IAVA", value:"2014-A-0142");

  script_name(english:"Ubuntu 10.04 LTS / 12.04 LTS / 14.04 LTS : bash vulnerabilities (USN-2380-1) (Shellshock)");
  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:
"Michal Zalewski discovered that Bash incorrectly handled parsing
certain function definitions. If an attacker were able to create an
environment variable containing a function definition with a very
specific name, these issues could possibly be used to bypass certain
environment restrictions and execute arbitrary code. (CVE-2014-6277,
CVE-2014-6278)

Please note that the previous Bash security update, USN-2364-1,
includes a hardening measure that prevents these issues from being
used in a Shellshock attack.

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 bash package.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:F/RL:OF/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"exploit_framework_core", value:"true");
  script_set_attribute(attribute:"metasploit_name", value:'CUPS Filter Bash Environment Variable Code Injection (Shellshock)');
  script_set_attribute(attribute:"exploit_framework_metasploit", value:"true");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:bash");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:10.04:-:lts");
  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:"patch_publication_date", value:"2014/10/09");
  script_set_attribute(attribute:"in_the_news", value:"true");
  script_set_attribute(attribute:"plugin_publication_date", value:"2014/10/11");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"Ubuntu Security Notice (C) 2014-2018 Canonical, Inc. / NASL script (C) 2014-2016 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:"^(10\.04|12\.04|14\.04)$", string:release)) audit(AUDIT_OS_NOT, "Ubuntu 10.04 / 12.04 / 14.04", "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:"10.04", pkgname:"bash", pkgver:"4.1-2ubuntu3.5")) flag++;
if (ubuntu_check(osver:"12.04", pkgname:"bash", pkgver:"4.2-2ubuntu2.6")) flag++;
if (ubuntu_check(osver:"14.04", pkgname:"bash", pkgver:"4.3-7ubuntu1.5")) flag++;

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    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, "bash");
}