Vulnerabilities > CVE-2016-3957 - Deserialization of Untrusted Data vulnerability in Web2Py

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-4030-1. 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(126174);
  script_version("1.3");
  script_cvs_date("Date: 2020/01/10");

  script_cve_id("CVE-2016-10321", "CVE-2016-3952", "CVE-2016-3953", "CVE-2016-3954", "CVE-2016-3957");
  script_xref(name:"USN", value:"4030-1");

  script_name(english:"Ubuntu 16.04 LTS : web2py vulnerabilities (USN-4030-1)");
  script_summary(english:"Checks dpkg output for updated packages.");

  script_set_attribute(
    attribute:"synopsis", 
    value:
"The remote Ubuntu host is missing one or more security-related
patches."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"It was discovered that web2py does not properly check denied hosts
before verifying passwords. An attacker could possibly use this issue
to perform brute-force attacks. (CVE-2016-10321)

It was discovered that web2py allows remote attackers to obtain
environment variable values. An attacker could possibly use this issue
to gain administrative access. (CVE-2016-3952)

It was discovered that web2py uses a hardcoded encryption key. An
attacker could possibly use this issue to execute arbitrary code.
(CVE-2016-3953, CVE-2016-3954, CVE-2016-3957).

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/4030-1/"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Update the affected python-gluon and / or python-web2py packages."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/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:H/I:H/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:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:python-gluon");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:python-web2py");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:16.04");

  script_set_attribute(attribute:"vuln_publication_date", value:"2017/04/10");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/06/21");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/06/24");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"Ubuntu Security Notice (C) 2019-2020 Canonical, Inc. / NASL script (C) 2019-2020 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:"^(16\.04)$", string:release)) audit(AUDIT_OS_NOT, "Ubuntu 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:"16.04", pkgname:"python-gluon", pkgver:"2.12.3-1ubuntu0.1")) flag++;
if (ubuntu_check(osver:"16.04", pkgname:"python-web2py", pkgver:"2.12.3-1ubuntu0.1")) 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, "python-gluon / python-web2py");
}