GLSA-202402-33 : PyYAML: Arbitrary Code Execution

#%NASL_MIN_LEVEL 80900
#
# (C) Tenable, Inc.
#
# @NOAGENT@
#
# The descriptive text and package checks in this plugin were
# extracted from Gentoo Linux Security Advisory GLSA 202402-33.
#
# The advisory text is Copyright (C) 2001-2021 Gentoo Foundation, Inc.
# and licensed under the Creative Commons - Attribution / Share Alike
# license. See http://creativecommons.org/licenses/by-sa/3.0/
#

include('compat.inc');

if (description)
{
  script_id(190999);
  script_version("1.0");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/02/26");

  script_cve_id("CVE-2020-14343");

  script_name(english:"GLSA-202402-33 : PyYAML: Arbitrary Code Execution");

  script_set_attribute(attribute:"synopsis", value:
"");
  script_set_attribute(attribute:"description", value:
"The remote host is affected by the vulnerability described in GLSA-202402-33 (PyYAML: Arbitrary Code Execution)

  - A vulnerability was discovered in the PyYAML library in versions before 5.4, where it is susceptible to
    arbitrary code execution when it processes untrusted YAML files through the full_load method or with the
    FullLoader loader. Applications that use the library to process untrusted input may be vulnerable to this
    flaw. This flaw allows an attacker to execute arbitrary code on the system by abusing the
    python/object/new constructor. This flaw is due to an incomplete fix for CVE-2020-1747. (CVE-2020-14343)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://security.gentoo.org/glsa/202402-33");
  script_set_attribute(attribute:"see_also", value:"https://bugs.gentoo.org/show_bug.cgi?id=766228");
  script_set_attribute(attribute:"solution", value:
"All PyYAML users should upgrade to the latest version:

          # emerge --sync
          # emerge --ask --oneshot --verbose >=dev-python/pyyaml-5.4");
  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: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:"cvss_score_source", value:"CVE-2020-14343");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"vuln_publication_date", value:"2021/01/21");
  script_set_attribute(attribute:"patch_publication_date", value:"2024/02/26");
  script_set_attribute(attribute:"plugin_publication_date", value:"2024/02/26");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:gentoo:linux:pyyaml");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:gentoo:linux");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Gentoo Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2024 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/Gentoo/release", "Host/Gentoo/qpkg-list");

  exit(0);
}
include('qpkg.inc');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item('Host/Gentoo/release')) audit(AUDIT_OS_NOT, 'Gentoo');
if (!get_kb_item('Host/Gentoo/qpkg-list')) audit(AUDIT_PACKAGE_LIST_MISSING);

var flag = 0;

var packages = [
  {
    'name' : 'dev-python/pyyaml',
    'unaffected' : make_list("ge 5.4"),
    'vulnerable' : make_list("lt 5.4")
  }
];

foreach var package( packages ) {
  if (isnull(package['unaffected'])) package['unaffected'] = make_list();
  if (isnull(package['vulnerable'])) package['vulnerable'] = make_list();
  if (qpkg_check(package: package['name'] , unaffected: package['unaffected'], vulnerable: package['vulnerable'])) flag++;
}


if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    extra      : qpkg_report_get()
  );
  exit(0);
}
else
{
  qpkg_tests = list_uniq(qpkg_tests);
  var tested = qpkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'PyYAML');
}