Debian dla-4418 : python3-mechanize - security update

#%NASL_MIN_LEVEL 80900
#
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Debian Security Advisory dla-4418. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#

include('compat.inc');

if (description)
{
  script_id(279499);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/12/22");

  script_cve_id("CVE-2021-32837");

  script_name(english:"Debian dla-4418 : python3-mechanize - security update");

  script_set_attribute(attribute:"synopsis", value:
"The remote Debian host is missing a security-related update.");
  script_set_attribute(attribute:"description", value:
"The remote Debian 11 host has a package installed that is affected by a vulnerability as referenced in the dla-4418
advisory.

    -------------------------------------------------------------------------
    Debian LTS Advisory DLA-4418-1                [email protected]
    https://www.debian.org/lts/security/                       Daniel Leidert
    December 22, 2025                             https://wiki.debian.org/LTS
    -------------------------------------------------------------------------

    Package        : python-mechanize
    Version        : 1:0.4.5-2+deb11u1
    CVE ID         : CVE-2021-32837

    Erik Krogh Kristensen and Rasmus Petersen from the GitHub Security Lab
    discovered a ReDoS (Regular Expression Denial of Service) vulnerability
    in python-mechanize, a library to automate interaction with websites
    modeled after the Perl module WWW::Mechanize, which could lead to
    Denial of Service when parsing a malformed authentication header.

    For Debian 11 bullseye, this problem has been fixed in version
    1:0.4.5-2+deb11u1.

    We recommend that you upgrade your python-mechanize packages.

    For the detailed security status of python-mechanize please refer to
    its security tracker page at:
    https://security-tracker.debian.org/tracker/python-mechanize

    Further information about Debian LTS security advisories, how to apply
    these updates to your system and frequently asked questions can be
    found at: https://wiki.debian.org/LTS
    Attachment:
    signature.asc
    Description: This is a digitally signed message part

Tenable has extracted the preceding description block directly from the Debian security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  # https://security-tracker.debian.org/tracker/source-package/python-mechanize
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?a6424ad8");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2021-32837");
  script_set_attribute(attribute:"see_also", value:"https://packages.debian.org/source/bullseye/python-mechanize");
  script_set_attribute(attribute:"solution", value:
"Upgrade the python3-mechanize packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/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");
  script_set_attribute(attribute:"cvss4_vector", value:"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N");
  script_set_attribute(attribute:"cvss4_threat_vector", value:"CVSS:4.0/E:P");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-32837");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2023/01/17");
  script_set_attribute(attribute:"patch_publication_date", value:"2025/12/22");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/12/22");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:python3-mechanize");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:11.0");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

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

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/Debian/release", "Host/Debian/dpkg-l");

  exit(0);
}

include('debian_package.inc');

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item("Host/Debian/dpkg-l")) audit(AUDIT_PACKAGE_LIST_MISSING);

var debian_release = get_kb_item('Host/Debian/release');
if ( isnull(debian_release) ) audit(AUDIT_OS_NOT, 'Debian');
debian_release = chomp(debian_release);
if (! preg(pattern:"^(11)\.[0-9]+", string:debian_release)) audit(AUDIT_OS_NOT, 'Debian 11.0', 'Debian ' + debian_release);
var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Debian', cpu);

var pkgs = [
    {'release': '11.0', 'prefix': 'python3-mechanize', 'reference': '1:0.4.5-2+deb11u1'}
];

var flag = 0;
foreach package_array ( pkgs ) {
  var _release = NULL;
  var prefix = NULL;
  var reference = NULL;
  if (!empty_or_null(package_array['release'])) _release = package_array['release'];
  if (!empty_or_null(package_array['prefix'])) prefix = package_array['prefix'];
  if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
  if (_release && prefix && reference) {
    if (deb_check(release:_release, prefix:prefix, reference:reference)) flag++;
  }
}

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    extra      : deb_report_get()
  );
  exit(0);
}
else
{
  var tested = deb_pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'python3-mechanize');
}