Amazon Linux 2 : libxml2 (ALAS-2020-1466)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux 2 Security Advisory ALAS-2020-1466.
#

include('compat.inc');

if (description)
{
  script_id(138855);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/02/29");

  script_cve_id(
    "CVE-2015-8035",
    "CVE-2016-5131",
    "CVE-2017-15412",
    "CVE-2017-18258",
    "CVE-2018-14404",
    "CVE-2018-14567"
  );
  script_xref(name:"ALAS", value:"2020-1466");

  script_name(english:"Amazon Linux 2 : libxml2 (ALAS-2020-1466)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Amazon Linux 2 host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"A NULL pointer dereference vulnerability exists in the
xpath.c:xmlXPathCompOpEval() function of libxml2 through 2.9.8 when
parsing an invalid XPath expression in the XPATH_OP_AND or XPATH_OP_OR
case. Applications processing untrusted XSL format inputs with the use
of the libxml2 library may be vulnerable to a denial of service attack
due to a crash of the application. (CVE-2018-14404)

Use after free in libxml2 before 2.9.5, as used in Google Chrome prior
to 63.0.3239.84 and other products, allowed a remote attacker to
potentially exploit heap corruption via a crafted HTML page.
(CVE-2017-15412)

A denial of service flaw was found in libxml2. A remote attacker could
provide a specially crafted XML or HTML file that, when processed by
an application using libxml2, would cause that application to crash.
(CVE-2015-8035)

libxml2 2.9.8, if --with-lzma is used, allows remote attackers to
cause a denial of service (infinite loop) via a crafted XML file that
triggers LZMA_MEMLIMIT_ERROR, as demonstrated by xmllint, a different
vulnerability than CVE-2015-8035 and CVE-2018-9251 . (CVE-2018-14567)

The xz_head function in xzlib.c in libxml2 before 2.9.6 allows remote
attackers to cause a denial of service (memory consumption) via a
crafted LZMA file, because the decoder functionality does not restrict
memory usage to what is required for a legitimate file.
(CVE-2017-18258)

Use-after-free vulnerability in libxml2 through 2.9.4, as used in
Google Chrome before 52.0.2743.82, allows remote attackers to cause a
denial of service or possibly have unspecified other impact via
vectors related to the XPointer range-to function. (CVE-2016-5131)");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/AL2/ALAS-2020-1466.html");
  script_set_attribute(attribute:"solution", value:
"Run 'yum update libxml2' to update your system.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/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:R/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-2017-15412");

  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:"2015/11/18");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/07/21");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/07/23");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:libxml2");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:libxml2-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:libxml2-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:libxml2-python");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:libxml2-static");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux:2");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2020-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");

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

  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/AmazonLinux/release");
if (isnull(release) || !strlen(release)) audit(AUDIT_OS_NOT, "Amazon Linux");
os_ver = pregmatch(pattern: "^AL(A|\d)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Amazon Linux");
os_ver = os_ver[1];
if (os_ver != "2")
{
  if (os_ver == 'A') os_ver = 'AMI';
  audit(AUDIT_OS_NOT, "Amazon Linux 2", "Amazon Linux " + os_ver);
}

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


flag = 0;
if (rpm_check(release:"AL2", reference:"libxml2-2.9.1-6.amzn2.4.1")) flag++;
if (rpm_check(release:"AL2", reference:"libxml2-debuginfo-2.9.1-6.amzn2.4.1")) flag++;
if (rpm_check(release:"AL2", reference:"libxml2-devel-2.9.1-6.amzn2.4.1")) flag++;
if (rpm_check(release:"AL2", reference:"libxml2-python-2.9.1-6.amzn2.4.1")) flag++;
if (rpm_check(release:"AL2", reference:"libxml2-static-2.9.1-6.amzn2.4.1")) flag++;

if (flag)
{
  if (report_verbosity > 0) security_warning(port:0, extra:rpm_report_get());
  else security_warning(0);
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "libxml2 / libxml2-debuginfo / libxml2-devel / libxml2-python / etc");
}