Linux Distros Unpatched Vulnerability : CVE-2021-3737

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##

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{
  script_id(224042);
  script_version("1.5");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/09/30");

  script_cve_id("CVE-2021-3737");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2021-3737");

  script_set_attribute(attribute:"synopsis", value:
"The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be
patched.");
  script_set_attribute(attribute:"description", value:
"The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied
patch available.

  - A flaw was found in python. An improperly handled HTTP response in the HTTP client code of python may
    allow a remote attacker, who controls the HTTP server, to make the client script enter an infinite loop,
    consuming CPU time. The highest threat from this vulnerability is to system availability. (CVE-2021-3737)

Note that Nessus relies on the presence of the package as reported by the vendor.");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/security/cve/cve-2021-3737");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2021-3737");
  script_set_attribute(attribute:"solution", value:
"There is no known solution at this time.");
  script_set_attribute(attribute:"agent", value:"unix");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:N/I:N/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:POC/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:P/RL:O/RC:C");
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  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
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  script_set_attribute(attribute:"vuln_publication_date", value:"2021/09/20");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/03/05");

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  script_copyright(english:"This script is Copyright (C) 2025 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("set_linux_os_id.nasl", "ssh_get_info2.nasl");
  script_require_keys("Host/OS/identifier", "Host/cpu", "Host/local_checks_enabled", "global_settings/vendor_unpatched");
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}

if (!get_kb_item("global_settings/vendor_unpatched")) exit(0, "Unpatched Vulnerabilities Detection not active.");
if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (empty_or_null(get_one_kb_item("Host/CentOS/rpm-list")) && empty_or_null(get_one_kb_item("Host/Debian/dpkg-l")) && empty_or_null(get_one_kb_item("Host/RedHat/rpm-list"))) audit(AUDIT_PACKAGE_LIST_MISSING);

include('linux_unpatched.inc');

var distro_constraints_array = {
  "Debian Linux-11": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "11",
        "pkgs": [
          {"reference": "idle-python2.7"},
          {"reference": "libpython2.7"},
          {"reference": "libpython2.7-dbg"},
          {"reference": "libpython2.7-dev"},
          {"reference": "libpython2.7-minimal"},
          {"reference": "libpython2.7-stdlib"},
          {"reference": "libpython2.7-testsuite"},
          {"reference": "python2.7"},
          {"reference": "python2.7-dbg"},
          {"reference": "python2.7-dev"},
          {"reference": "python2.7-doc"},
          {"reference": "python2.7-examples"},
          {"reference": "python2.7-minimal"}
        ]
      }
    ]
  },
  "CentOS Linux-7": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "7",
        "pkgs": [
          {"reference": "python"},
          {"reference": "python-debug"},
          {"reference": "python-devel"},
          {"reference": "python-libs"},
          {"reference": "python-test"},
          {"reference": "python-tools"},
          {"reference": "tkinter"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-7": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "7",
        "pkgs": [
          {"reference": "python"},
          {"reference": "python-debug"},
          {"reference": "python-devel"},
          {"reference": "python-libs"},
          {"reference": "python-test"},
          {"reference": "python-tools"},
          {"reference": "tkinter"}
        ]
      }
    ]
  },
  "CentOS Linux-8": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "8",
        "pkgs": [
          {"reference": "python-PyMySQL"},
          {"reference": "python-distro"},
          {"reference": "python-docs"},
          {"reference": "python-docutils"},
          {"reference": "python-nose"},
          {"reference": "python-nose-docs"},
          {"reference": "python-pygments"},
          {"reference": "python-pymongo"},
          {"reference": "python-pymongo-doc"},
          {"reference": "python-sqlalchemy"},
          {"reference": "python-sqlalchemy-doc"},
          {"reference": "python-virtualenv"},
          {"reference": "python-virtualenv-doc"},
          {"reference": "python-wheel"},
          {"reference": "python2"},
          {"reference": "python2-debug"},
          {"reference": "python2-devel"},
          {"reference": "python2-libs"},
          {"reference": "python2-test"},
          {"reference": "python2-tkinter"},
          {"reference": "python2-tools"},
          {"reference": "python3-PyMySQL"},
          {"reference": "python3-bson"},
          {"reference": "python3-distro"},
          {"reference": "python3-docs"},
          {"reference": "python3-docutils"},
          {"reference": "python3-nose"},
          {"reference": "python3-pygments"},
          {"reference": "python3-pymongo"},
          {"reference": "python3-pymongo-gridfs"},
          {"reference": "python3-scipy"},
          {"reference": "python3-sqlalchemy"},
          {"reference": "python3-virtualenv"},
          {"reference": "python3-wheel"},
          {"reference": "python3-wheel-wheel"},
          {"reference": "python36"},
          {"reference": "python36-debug"},
          {"reference": "python36-devel"},
          {"reference": "python36-rpm-macros"},
          {"reference": "scipy"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-8": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "8",
        "pkgs": [
          {"reference": "python-PyMySQL"},
          {"reference": "python-distro"},
          {"reference": "python-docs"},
          {"reference": "python-docutils"},
          {"reference": "python-nose"},
          {"reference": "python-nose-docs"},
          {"reference": "python-pygments"},
          {"reference": "python-pymongo"},
          {"reference": "python-pymongo-doc"},
          {"reference": "python-sqlalchemy"},
          {"reference": "python-sqlalchemy-doc"},
          {"reference": "python-virtualenv"},
          {"reference": "python-virtualenv-doc"},
          {"reference": "python-wheel"},
          {"reference": "python2"},
          {"reference": "python2-debug"},
          {"reference": "python2-devel"},
          {"reference": "python2-libs"},
          {"reference": "python2-test"},
          {"reference": "python2-tkinter"},
          {"reference": "python2-tools"},
          {"reference": "python3-PyMySQL"},
          {"reference": "python3-bson"},
          {"reference": "python3-distro"},
          {"reference": "python3-docs"},
          {"reference": "python3-docutils"},
          {"reference": "python3-nose"},
          {"reference": "python3-pygments"},
          {"reference": "python3-pymongo"},
          {"reference": "python3-pymongo-gridfs"},
          {"reference": "python3-scipy"},
          {"reference": "python3-sqlalchemy"},
          {"reference": "python3-virtualenv"},
          {"reference": "python3-wheel"},
          {"reference": "python3-wheel-wheel"},
          {"reference": "python36"},
          {"reference": "python36-debug"},
          {"reference": "python36-devel"},
          {"reference": "python36-rpm-macros"},
          {"reference": "scipy"}
        ]
      }
    ]
  }
};

var distro_constraints_values = linux_unpatched::get_distro_constraints(distro_constraints_arr:distro_constraints_array);
if (empty_or_null(distro_constraints_values)) audit(AUDIT_HOST_NOT, 'affected');
var report = linux_unpatched::check_unpatched_constraints(distro_constraints_values:distro_constraints_values);

if (!empty_or_null(report))
{
  security_report_v4(
      port       : 0,
      severity   : SECURITY_HOLE,
      extra      : report
  );
  exit(0);
}
else
{
  audit(AUDIT_HOST_NOT, 'affected');
}