Amazon Linux AMI : python27 (ALAS-2022-1593)

##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux AMI Security Advisory ALAS-2022-1593.
##

include('compat.inc');

if (description)
{
  script_id(162008);
  script_version("1.4");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/10/25");

  script_cve_id(
    "CVE-2020-27619",
    "CVE-2021-3733",
    "CVE-2021-3737",
    "CVE-2021-4189",
    "CVE-2021-23336",
    "CVE-2022-0391"
  );
  script_xref(name:"IAVA", value:"2021-A-0052-S");
  script_xref(name:"IAVA", value:"2021-A-0263-S");
  script_xref(name:"IAVA", value:"2021-A-0497-S");

  script_name(english:"Amazon Linux AMI : python27 (ALAS-2022-1593)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Amazon Linux AMI host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"The version of python27 installed on the remote host is prior to 2.7.18-2.142. It is, therefore, affected by multiple
vulnerabilities as referenced in the ALAS-2022-1593 advisory.

  - In Python 3 through 3.9.0, the Lib/test/multibytecodec_support.py CJK codec tests call eval() on content
    retrieved via HTTP. (CVE-2020-27619)

  - The package python/cpython from 0 and before 3.6.13, from 3.7.0 and before 3.7.10, from 3.8.0 and before
    3.8.8, from 3.9.0 and before 3.9.2 are vulnerable to Web Cache Poisoning via urllib.parse.parse_qsl and
    urllib.parse.parse_qs by using a vector called parameter cloaking. When the attacker can separate query
    parameters using a semicolon (;), they can cause a difference in the interpretation of the request between
    the proxy (running with default configuration) and the server. This can result in malicious requests being
    cached as completely safe ones, as the proxy would usually not see the semicolon as a separator, and
    therefore would not include it in a cache key of an unkeyed parameter. (CVE-2021-23336)

  - There's a flaw in urllib's AbstractBasicAuthHandler class. An attacker who controls a malicious HTTP
    server that an HTTP client (such as web browser) connects to, could trigger a Regular Expression Denial of
    Service (ReDOS) during an authentication request with a specially crafted payload that is sent by the
    server to the client. The greatest threat that this flaw poses is to application availability.
    (CVE-2021-3733)

  - 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)

  - A flaw was found in Python, specifically within the urllib.parse module. This module helps break Uniform
    Resource Locator (URL) strings into components. The issue involves how the urlparse method does not
    sanitize input and allows characters like '\r' and '
' in the URL path. This flaw allows an attacker to
    input a crafted URL, leading to injection attacks. This flaw affects Python versions prior to 3.10.0b1,
    3.9.5, 3.8.11, 3.7.11 and 3.6.14. (CVE-2022-0391)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/ALAS-2022-1593.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2020-27619.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-23336.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-3733.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-3737.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-4189.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2022-0391.html");
  script_set_attribute(attribute:"solution", value:
"Run 'yum update python27' to update your system.");
  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:POC/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:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-27619");

  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:"2020/10/22");
  script_set_attribute(attribute:"patch_publication_date", value:"2022/05/31");
  script_set_attribute(attribute:"plugin_publication_date", value:"2022/06/10");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:python27");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:python27-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:python27-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:python27-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:python27-test");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:python27-tools");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2022-2023 and is owned by Tenable, Inc. or an Affiliate thereof.");

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

  exit(0);
}

include("rpm.inc");

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);

var release = get_kb_item("Host/AmazonLinux/release");
if (isnull(release) || !strlen(release)) audit(AUDIT_OS_NOT, "Amazon Linux");
var os_ver = pregmatch(pattern: "^AL(A|\d)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Amazon Linux");
var os_ver = os_ver[1];
if (os_ver != "A")
{
  if (os_ver == 'A') os_ver = 'AMI';
  audit(AUDIT_OS_NOT, "Amazon Linux AMI", "Amazon Linux " + os_ver);
}

if (!get_kb_item("Host/AmazonLinux/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);

var pkgs = [
    {'reference':'python27-2.7.18-2.142.amzn1', 'cpu':'i686', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'python27-2.7.18-2.142.amzn1', 'cpu':'x86_64', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'python27-debuginfo-2.7.18-2.142.amzn1', 'cpu':'i686', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'python27-debuginfo-2.7.18-2.142.amzn1', 'cpu':'x86_64', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'python27-devel-2.7.18-2.142.amzn1', 'cpu':'i686', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'python27-devel-2.7.18-2.142.amzn1', 'cpu':'x86_64', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'python27-libs-2.7.18-2.142.amzn1', 'cpu':'i686', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'python27-libs-2.7.18-2.142.amzn1', 'cpu':'x86_64', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'python27-test-2.7.18-2.142.amzn1', 'cpu':'i686', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'python27-test-2.7.18-2.142.amzn1', 'cpu':'x86_64', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'python27-tools-2.7.18-2.142.amzn1', 'cpu':'i686', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'python27-tools-2.7.18-2.142.amzn1', 'cpu':'x86_64', 'release':'ALA', 'rpm_spec_vers_cmp':TRUE}
];

var flag = 0;
foreach var package_array ( pkgs ) {
  var reference = NULL;
  var release = NULL;
  var sp = NULL;
  var cpu = NULL;
  var el_string = NULL;
  var rpm_spec_vers_cmp = NULL;
  var epoch = NULL;
  var allowmaj = NULL;
  var exists_check = NULL;
  if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
  if (!empty_or_null(package_array['release'])) release = package_array['release'];
  if (!empty_or_null(package_array['sp'])) sp = package_array['sp'];
  if (!empty_or_null(package_array['cpu'])) cpu = package_array['cpu'];
  if (!empty_or_null(package_array['el_string'])) el_string = package_array['el_string'];
  if (!empty_or_null(package_array['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = package_array['rpm_spec_vers_cmp'];
  if (!empty_or_null(package_array['epoch'])) epoch = package_array['epoch'];
  if (!empty_or_null(package_array['allowmaj'])) allowmaj = package_array['allowmaj'];
  if (!empty_or_null(package_array['exists_check'])) exists_check = package_array['exists_check'];
  if (reference && release && (!exists_check || rpm_exists(release:release, rpm:exists_check))) {
    if (rpm_check(release:release, sp:sp, cpu:cpu, reference:reference, epoch:epoch, el_string:el_string, rpm_spec_vers_cmp:rpm_spec_vers_cmp, allowmaj:allowmaj)) flag++;
  }
}

if (flag)
{
  security_report_v4(
      port       : 0,
      severity   : SECURITY_HOLE,
      extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  var tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "python27 / python27-debuginfo / python27-devel / etc");
}