EulerOS Virtualization 2.9.0 : pyyaml (EulerOS-SA-2021-1755)

#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#

include('deprecated_nasl_level.inc');
include('compat.inc');

if (description)
{
  script_id(148591);
  script_version("1.7");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/12/02");

  script_cve_id("CVE-2020-14343");
  script_xref(name:"IAVA", value:"2021-A-0463");

  script_name(english:"EulerOS Virtualization 2.9.0 : pyyaml (EulerOS-SA-2021-1755)");

  script_set_attribute(attribute:"synopsis", value:
"The remote EulerOS Virtualization host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"According to the version of the pyyaml package installed, the EulerOS
Virtualization installation on the remote host is affected by the
following vulnerability :

  - 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 Tenable Network Security has extracted the preceding
description block directly from the EulerOS security advisory. Tenable
has attempted to automatically clean and format it as much as possible
without introducing additional issues.");
  # https://developer.huaweicloud.com/ict/en/site-euleros/euleros/security-advisories/EulerOS-SA-2021-1755
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?12e9efce");
  script_set_attribute(attribute:"solution", value:
"Update the affected pyyaml package.");
  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: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-2020-14343");

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

  script_set_attribute(attribute:"patch_publication_date", value:"2021/04/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/04/15");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:python3-pyyaml");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:huawei:euleros:uvp:2.9.0");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2021-2025 and is owned by Tenable, Inc. or an Affiliate thereof.");

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

  exit(0);
}

include("audit.inc");
include("global_settings.inc");
include("rpm.inc");

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

release = get_kb_item("Host/EulerOS/release");
if (isnull(release) || release !~ "^EulerOS") audit(AUDIT_OS_NOT, "EulerOS");
uvp = get_kb_item("Host/EulerOS/uvp_version");
if (uvp != "2.9.0") audit(AUDIT_OS_NOT, "EulerOS Virtualization 2.9.0");
if (!get_kb_item("Host/EulerOS/rpm-list")) 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$" && "aarch64" >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "EulerOS", cpu);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_ARCH_NOT, "i686 / x86_64", cpu);

flag = 0;

pkgs = ["python3-pyyaml-5.3.1-1.h2.eulerosv2r9"];

foreach (pkg in pkgs)
  if (rpm_check(release:"EulerOS-2.0", reference:pkg)) flag++;

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "pyyaml");
}