Rocky Linux 8 : tigervnc (RLSA-2024:2037)

2024-05-0600:00:00

www.tenable.com

rocky linux 8

x.org server

procxigetselectedevents

heap-based buffer over-read

vulnerability

memory leakage

segmentation faults

cve-2024-31080

procxipassivegrabdevice

use-after-free

procrenderaddglyphs

arbitrary code execution

CVSS3

7.8

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

AI Score

7.4

Confidence

Low

EPSS

0.001

Percentile

17.1%

JSON

The remote Rocky Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the RLSA-2024:2037 advisory.

A heap-based buffer over-read vulnerability was found in the X.org server’s ProcXIGetSelectedEvents() function. This issue occurs when byte-swapped length values are used in replies, potentially leading to memory leakage and segmentation faults, particularly when triggered by a client with a different endianness. This vulnerability could be exploited by an attacker to cause the X server to read heap memory values and then transmit them back to the client until encountering an unmapped page, resulting in a crash. Despite the attacker’s inability to control the specific memory copied into the replies, the small length values typically stored in a 32-bit integer can result in significant attempted out-of-bounds reads. (CVE-2024-31080)
A heap-based buffer over-read vulnerability was found in the X.org server’s ProcXIPassiveGrabDevice() function. This issue occurs when byte-swapped length values are used in replies, potentially leading to memory leakage and segmentation faults, particularly when triggered by a client with a different endianness. This vulnerability could be exploited by an attacker to cause the X server to read heap memory values and then transmit them back to the client until encountering an unmapped page, resulting in a crash. Despite the attacker’s inability to control the specific memory copied into the replies, the small length values typically stored in a 32-bit integer can result in significant attempted out-of-bounds reads. (CVE-2024-31081)
A use-after-free vulnerability was found in the ProcRenderAddGlyphs() function of Xorg servers. This issue occurs when AllocateGlyph() is called to store new glyphs sent by the client to the X server, potentially resulting in multiple entries pointing to the same non-refcounted glyphs. Consequently, ProcRenderAddGlyphs() may free a glyph, leading to a use-after-free scenario when the same glyph pointer is subsequently accessed. This flaw allows an authenticated attacker to execute arbitrary code on the system by sending a specially crafted request. (CVE-2024-31083)

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

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The package checks in this plugin were extracted from
# Rocky Linux Security Advisory RLSA-2024:2037.
##

include('compat.inc');

if (description)
{
  script_id(195009);
  script_version("1.0");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/05/06");

  script_cve_id("CVE-2024-31080", "CVE-2024-31081", "CVE-2024-31083");
  script_xref(name:"RLSA", value:"2024:2037");

  script_name(english:"Rocky Linux 8 : tigervnc (RLSA-2024:2037)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Rocky Linux host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The remote Rocky Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the
RLSA-2024:2037 advisory.

  - A heap-based buffer over-read vulnerability was found in the X.org server's ProcXIGetSelectedEvents()
    function. This issue occurs when byte-swapped length values are used in replies, potentially leading to
    memory leakage and segmentation faults, particularly when triggered by a client with a different
    endianness. This vulnerability could be exploited by an attacker to cause the X server to read heap memory
    values and then transmit them back to the client until encountering an unmapped page, resulting in a
    crash. Despite the attacker's inability to control the specific memory copied into the replies, the small
    length values typically stored in a 32-bit integer can result in significant attempted out-of-bounds
    reads. (CVE-2024-31080)

  - A heap-based buffer over-read vulnerability was found in the X.org server's ProcXIPassiveGrabDevice()
    function. This issue occurs when byte-swapped length values are used in replies, potentially leading to
    memory leakage and segmentation faults, particularly when triggered by a client with a different
    endianness. This vulnerability could be exploited by an attacker to cause the X server to read heap memory
    values and then transmit them back to the client until encountering an unmapped page, resulting in a
    crash. Despite the attacker's inability to control the specific memory copied into the replies, the small
    length values typically stored in a 32-bit integer can result in significant attempted out-of-bounds
    reads. (CVE-2024-31081)

  - A use-after-free vulnerability was found in the ProcRenderAddGlyphs() function of Xorg servers. This issue
    occurs when AllocateGlyph() is called to store new glyphs sent by the client to the X server, potentially
    resulting in multiple entries pointing to the same non-refcounted glyphs. Consequently,
    ProcRenderAddGlyphs() may free a glyph, leading to a use-after-free scenario when the same glyph pointer
    is subsequently accessed. This flaw allows an authenticated attacker to execute arbitrary code on the
    system by sending a specially crafted request. (CVE-2024-31083)

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://errata.rockylinux.org/RLSA-2024:2037");
  script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=2271997");
  script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=2271998");
  script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=2272000");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:P/I:P/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:L/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:"cvss_score_source", value:"CVE-2024-31081");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2024-31083");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"vuln_publication_date", value:"2024/04/04");
  script_set_attribute(attribute:"patch_publication_date", value:"2024/05/06");
  script_set_attribute(attribute:"plugin_publication_date", value:"2024/05/06");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:rocky:linux:tigervnc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:rocky:linux:tigervnc-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:rocky:linux:tigervnc-debugsource");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:rocky:linux:tigervnc-icons");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:rocky:linux:tigervnc-license");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:rocky:linux:tigervnc-selinux");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:rocky:linux:tigervnc-server");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:rocky:linux:tigervnc-server-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:rocky:linux:tigervnc-server-minimal");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:rocky:linux:tigervnc-server-minimal-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:rocky:linux:tigervnc-server-module");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:rocky:linux:tigervnc-server-module-debuginfo");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:rocky:linux:8");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 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/RockyLinux/release", "Host/RockyLinux/rpm-list", "Host/cpu");

  exit(0);
}


include('rpm.inc');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_release = get_kb_item('Host/RockyLinux/release');
if (isnull(os_release) || 'Rocky Linux' >!< os_release) audit(AUDIT_OS_NOT, 'Rocky Linux');
var os_ver = pregmatch(pattern: "Rocky(?: Linux)? release ([0-9]+(\.[0-9]+)?)", string:os_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'Rocky Linux');
os_ver = os_ver[1];
if (! preg(pattern:"^8([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, 'Rocky Linux 8.x', 'Rocky Linux ' + os_ver);

if (!get_kb_item('Host/RockyLinux/rpm-list')) audit(AUDIT_PACKAGE_LIST_MISSING);

var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 's390' >!< cpu && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Rocky Linux', cpu);

var pkgs = [
    {'reference':'tigervnc-1.13.1-2.el8_9.10', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'tigervnc-1.13.1-2.el8_9.10', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'tigervnc-debuginfo-1.13.1-2.el8_9.10', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'tigervnc-debuginfo-1.13.1-2.el8_9.10', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'tigervnc-debugsource-1.13.1-2.el8_9.10', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'tigervnc-debugsource-1.13.1-2.el8_9.10', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'tigervnc-icons-1.13.1-2.el8_9.10', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'tigervnc-license-1.13.1-2.el8_9.10', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'tigervnc-selinux-1.13.1-2.el8_9.10', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'tigervnc-server-1.13.1-2.el8_9.10', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'tigervnc-server-1.13.1-2.el8_9.10', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'tigervnc-server-debuginfo-1.13.1-2.el8_9.10', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'tigervnc-server-debuginfo-1.13.1-2.el8_9.10', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'tigervnc-server-minimal-1.13.1-2.el8_9.10', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'tigervnc-server-minimal-1.13.1-2.el8_9.10', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'tigervnc-server-minimal-debuginfo-1.13.1-2.el8_9.10', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'tigervnc-server-minimal-debuginfo-1.13.1-2.el8_9.10', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'tigervnc-server-module-1.13.1-2.el8_9.10', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'tigervnc-server-module-1.13.1-2.el8_9.10', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'tigervnc-server-module-debuginfo-1.13.1-2.el8_9.10', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'tigervnc-server-module-debuginfo-1.13.1-2.el8_9.10', 'cpu':'x86_64', 'release':'8', '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 = 'Rocky-' + 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, 'tigervnc / tigervnc-debuginfo / tigervnc-debugsource / etc');
}