Amazon Linux 2 : libX11 (ALAS-2019-1226)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux 2 Security Advisory ALAS-2019-1226.
#

include("compat.inc");

if (description)
{
  script_id(125898);
  script_version("1.2");
  script_cvs_date("Date: 2020/01/10");

  script_cve_id("CVE-2018-14598", "CVE-2018-14599");
  script_xref(name:"ALAS", value:"2019-1226");

  script_name(english:"Amazon Linux 2 : libX11 (ALAS-2019-1226)");
  script_summary(english:"Checks rpm output for the updated packages");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote Amazon Linux 2 host is missing a security update."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"An off-by-one error has been discovered in libX11 in functions
XGetFontPath(), XListExtensions(), and XListFonts(). An attacker who
can either configure a malicious X server or modify the data coming
from one could use this flaw to make the program crash or have other
unspecified effects, caused by the memory corruption. (CVE-2018-14599)

It was discovered that libX11 does not properly validate input coming
from the server, causing XListExtensions() and XGetFontPath()
functions to produce an invalid list of elements that in turn make
XFreeExtensionsList() and XFreeFontPath() access invalid memory. An
attacker who can either configure a malicious X server or modify the
data coming from one, could use this flaw to crash the application
using libX11, resulting in a denial of service. (CVE-2018-14598)"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://alas.aws.amazon.com/AL2/ALAS-2019-1226.html"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Run 'yum update libX11' 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:U/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:U/RL:O/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:libX11");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:libX11-common");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:libX11-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:libX11-devel");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux:2");

  script_set_attribute(attribute:"vuln_publication_date", value:"2018/08/24");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/06/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/06/14");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"Amazon Linux Local Security Checks");

  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:"libX11-1.6.5-2.amzn2.0.2")) flag++;
if (rpm_check(release:"AL2", reference:"libX11-common-1.6.5-2.amzn2.0.2")) flag++;
if (rpm_check(release:"AL2", reference:"libX11-debuginfo-1.6.5-2.amzn2.0.2")) flag++;
if (rpm_check(release:"AL2", reference:"libX11-devel-1.6.5-2.amzn2.0.2")) flag++;

if (flag)
{
  if (report_verbosity > 0) security_hole(port:0, extra:rpm_report_get());
  else security_hole(0);
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "libX11 / libX11-common / libX11-debuginfo / libX11-devel");
}