Amazon Linux 2 : ghostscript (ALAS-2023-2019)

2023-05-0200:00:00

www.tenable.com

amazon linux 2

ghostscript

vulnerability

alas-2023-2019

buffer overflow

postscript interpreter

EPSS

0.004

Percentile

75.3%

JSON

The version of ghostscript installed on the remote host is prior to 9.25-5. It is, therefore, affected by a vulnerability as referenced in the ALAS2-2023-2019 advisory.

In Artifex Ghostscript through 10.01.0, there is a buffer overflow leading to potential corruption of data internal to the PostScript interpreter, in base/sbcp.c. This affects BCPEncode, BCPDecode, TBCPEncode, and TBCPDecode. If the write buffer is filled to one byte less than full, and one then tries to write an escaped character, two bytes are written. (CVE-2023-28879)

Note that Nessus has not tested for this issue but has instead relied only on the application’s self-reported version number.

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux 2 Security Advisory ALAS-2023-2019.
##

include('compat.inc');

if (description)
{
  script_id(175012);
  script_version("1.4");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/09/27");

  script_cve_id("CVE-2023-28879");
  script_xref(name:"IAVB", value:"2023-B-0023-S");

  script_name(english:"Amazon Linux 2 : ghostscript (ALAS-2023-2019)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Amazon Linux 2 host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"The version of ghostscript installed on the remote host is prior to 9.25-5. It is, therefore, affected by a
vulnerability as referenced in the ALAS2-2023-2019 advisory.

  - In Artifex Ghostscript through 10.01.0, there is a buffer overflow leading to potential corruption of data
    internal to the PostScript interpreter, in base/sbcp.c. This affects BCPEncode, BCPDecode, TBCPEncode, and
    TBCPDecode. If the write buffer is filled to one byte less than full, and one then tries to write an
    escaped character, two bytes are written. (CVE-2023-28879)

Note that Nessus has not tested for this issue 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/AL2/ALAS-2023-2019.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2023-28879.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/faqs.html");
  script_set_attribute(attribute:"solution", value:
"Run 'yum update ghostscript' to update your system.");
  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-2023-28879");

  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:"2023/03/31");
  script_set_attribute(attribute:"patch_publication_date", value:"2023/04/27");
  script_set_attribute(attribute:"plugin_publication_date", value:"2023/05/02");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ghostscript");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ghostscript-cups");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ghostscript-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ghostscript-doc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ghostscript-gtk");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:libgs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:libgs-devel");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux:2");
  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:"Amazon Linux Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 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 alas_release = get_kb_item("Host/AmazonLinux/release");
if (isnull(alas_release) || !strlen(alas_release)) audit(AUDIT_OS_NOT, "Amazon Linux");
var os_ver = pregmatch(pattern: "^AL(A|\d+|-\d+)", string:alas_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);

var pkgs = [
    {'reference':'ghostscript-9.25-5.amzn2.0.3', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ghostscript-9.25-5.amzn2.0.3', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ghostscript-9.25-5.amzn2.0.3', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ghostscript-cups-9.25-5.amzn2.0.3', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ghostscript-cups-9.25-5.amzn2.0.3', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ghostscript-cups-9.25-5.amzn2.0.3', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ghostscript-debuginfo-9.25-5.amzn2.0.3', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ghostscript-debuginfo-9.25-5.amzn2.0.3', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ghostscript-debuginfo-9.25-5.amzn2.0.3', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ghostscript-doc-9.25-5.amzn2.0.3', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ghostscript-gtk-9.25-5.amzn2.0.3', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ghostscript-gtk-9.25-5.amzn2.0.3', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ghostscript-gtk-9.25-5.amzn2.0.3', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'libgs-9.25-5.amzn2.0.3', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'libgs-9.25-5.amzn2.0.3', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'libgs-9.25-5.amzn2.0.3', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'libgs-devel-9.25-5.amzn2.0.3', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'libgs-devel-9.25-5.amzn2.0.3', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'libgs-devel-9.25-5.amzn2.0.3', 'cpu':'x86_64', 'release':'AL2', '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, "ghostscript / ghostscript-cups / ghostscript-debuginfo / etc");
}