RHEL 5 : openssh (RHSA-2009:1287)

#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Red Hat Security Advisory RHSA-2009:1287. The text 
# itself is copyright (C) Red Hat, Inc.
#

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

if (description)
{
  script_id(40837);
  script_version("1.27");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/11/04");

  script_cve_id("CVE-2008-5161");
  script_bugtraq_id(32319);
  script_xref(name:"RHSA", value:"2009:1287");

  script_name(english:"RHEL 5 : openssh (RHSA-2009:1287)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Red Hat host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"The remote Redhat Enterprise Linux 5 host has packages installed that are affected by a vulnerability as referenced in
the RHSA-2009:1287 advisory.

    OpenSSH is OpenBSD's SSH (Secure Shell) protocol implementation. These
    packages include the core files necessary for both the OpenSSH client and
    server.

    A flaw was found in the SSH protocol. An attacker able to perform a
    man-in-the-middle attack may be able to obtain a portion of plain text from
    an arbitrary ciphertext block when a CBC mode cipher was used to encrypt
    SSH communication. This update helps mitigate this attack: OpenSSH clients
    and servers now prefer CTR mode ciphers to CBC mode, and the OpenSSH server
    now reads SSH packets up to their full possible length when corruption is
    detected, rather than reporting errors early, reducing the possibility of
    successful plain text recovery. (CVE-2008-5161)

    This update also fixes the following bug:

    * the ssh client hung when trying to close a session in which a background
    process still held tty file descriptors open. With this update, this
    so-called hang on exit error no longer occurs and the ssh client closes
    the session immediately. (BZ#454812)

    In addition, this update adds the following enhancements:

    * the SFTP server can now chroot users to various directories, including
    a user's home directory, after log in. A new configuration option --
    ChrootDirectory -- has been added to /etc/ssh/sshd_config for setting
    this up (the default is not to chroot users). Details regarding configuring
    this new option are in the sshd_config(5) manual page. (BZ#440240)

    * the executables which are part of the OpenSSH FIPS module which is being
    validated will check their integrity and report their FIPS mode status to
    the system log or to the terminal. (BZ#467268, BZ#492363)

    All OpenSSH users are advised to upgrade to these updated packages, which
    contain backported patches to resolve these issues and add these
    enhancements. After installing this update, the OpenSSH server daemon
    (sshd) will be restarted automatically.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  # https://access.redhat.com/security/data/csaf/v2/advisories/2009/rhsa-2009_1287.json
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?54003569");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/security/updates/classification/#low");
  script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=440240");
  script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=472068");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/errata/RHSA-2009:1287");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:H/Au:N/C:P/I:N/A:N");
  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:C/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-2008-5161");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2008/11/19");
  script_set_attribute(attribute:"patch_publication_date", value:"2009/09/02");
  script_set_attribute(attribute:"plugin_publication_date", value:"2009/09/02");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:openssh");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:openssh-askpass");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:openssh-clients");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:openssh-server");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:5");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2009-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");

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

  exit(0);
}


include('rpm.inc');
include('rhel.inc');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_release = get_kb_item('Host/RedHat/release');
if (isnull(os_release) || 'Red Hat' >!< os_release) audit(AUDIT_OS_NOT, 'Red Hat');
var os_ver = pregmatch(pattern: "Red Hat Enterprise Linux.*release ([0-9]+(\.[0-9]+)?)", string:os_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'Red Hat');
os_ver = os_ver[1];
if (!rhel_check_release(operator: 'ge', os_version: os_ver, rhel_version: '5')) audit(AUDIT_OS_NOT, 'Red Hat 5.x', 'Red Hat ' + os_ver);

if (!get_kb_item('Host/RedHat/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 && 'ppc' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Red Hat', cpu);

var constraints = [
  {
    'repo_relative_urls': [
      'content/dist/rhel/client/5/5Client/i386/debug',
      'content/dist/rhel/client/5/5Client/i386/os',
      'content/dist/rhel/client/5/5Client/i386/source/SRPMS',
      'content/dist/rhel/client/5/5Client/x86_64/debug',
      'content/dist/rhel/client/5/5Client/x86_64/os',
      'content/dist/rhel/client/5/5Client/x86_64/source/SRPMS',
      'content/dist/rhel/power/5/5Server/ppc/debug',
      'content/dist/rhel/power/5/5Server/ppc/os',
      'content/dist/rhel/power/5/5Server/ppc/source/SRPMS',
      'content/dist/rhel/server/5/5Server/i386/debug',
      'content/dist/rhel/server/5/5Server/i386/os',
      'content/dist/rhel/server/5/5Server/i386/source/SRPMS',
      'content/dist/rhel/server/5/5Server/x86_64/debug',
      'content/dist/rhel/server/5/5Server/x86_64/os',
      'content/dist/rhel/server/5/5Server/x86_64/source/SRPMS',
      'content/dist/rhel/system-z/5/5Server/s390x/debug',
      'content/dist/rhel/system-z/5/5Server/s390x/os',
      'content/dist/rhel/system-z/5/5Server/s390x/source/SRPMS',
      'content/dist/rhel/workstation/5/5Client/i386/desktop/debug',
      'content/dist/rhel/workstation/5/5Client/i386/desktop/os',
      'content/dist/rhel/workstation/5/5Client/i386/desktop/source/SRPMS',
      'content/dist/rhel/workstation/5/5Client/x86_64/desktop/debug',
      'content/dist/rhel/workstation/5/5Client/x86_64/desktop/os',
      'content/dist/rhel/workstation/5/5Client/x86_64/desktop/source/SRPMS',
      'content/fastrack/rhel/client/5/i386/debug',
      'content/fastrack/rhel/client/5/i386/os',
      'content/fastrack/rhel/client/5/i386/source/SRPMS',
      'content/fastrack/rhel/client/5/x86_64/debug',
      'content/fastrack/rhel/client/5/x86_64/os',
      'content/fastrack/rhel/client/5/x86_64/source/SRPMS',
      'content/fastrack/rhel/power/5/ppc/debug',
      'content/fastrack/rhel/power/5/ppc/os',
      'content/fastrack/rhel/power/5/ppc/source/SRPMS',
      'content/fastrack/rhel/server/5/i386/debug',
      'content/fastrack/rhel/server/5/i386/os',
      'content/fastrack/rhel/server/5/i386/source/SRPMS',
      'content/fastrack/rhel/server/5/x86_64/debug',
      'content/fastrack/rhel/server/5/x86_64/os',
      'content/fastrack/rhel/server/5/x86_64/source/SRPMS',
      'content/fastrack/rhel/system-z/5/s390x/debug',
      'content/fastrack/rhel/system-z/5/s390x/os',
      'content/fastrack/rhel/system-z/5/s390x/source/SRPMS',
      'content/fastrack/rhel/workstation/5/i386/desktop/debug',
      'content/fastrack/rhel/workstation/5/i386/desktop/os',
      'content/fastrack/rhel/workstation/5/i386/desktop/source/SRPMS',
      'content/fastrack/rhel/workstation/5/x86_64/desktop/debug',
      'content/fastrack/rhel/workstation/5/x86_64/desktop/os',
      'content/fastrack/rhel/workstation/5/x86_64/desktop/source/SRPMS'
    ],
    'pkgs': [
      {'reference':'openssh-4.3p2-36.el5', 'cpu':'i386', 'release':'5', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
      {'reference':'openssh-4.3p2-36.el5', 'cpu':'ppc', 'release':'5', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
      {'reference':'openssh-4.3p2-36.el5', 'cpu':'s390x', 'release':'5', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
      {'reference':'openssh-4.3p2-36.el5', 'cpu':'x86_64', 'release':'5', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
      {'reference':'openssh-askpass-4.3p2-36.el5', 'cpu':'i386', 'release':'5', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
      {'reference':'openssh-askpass-4.3p2-36.el5', 'cpu':'ppc', 'release':'5', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
      {'reference':'openssh-askpass-4.3p2-36.el5', 'cpu':'s390x', 'release':'5', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
      {'reference':'openssh-askpass-4.3p2-36.el5', 'cpu':'x86_64', 'release':'5', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
      {'reference':'openssh-clients-4.3p2-36.el5', 'cpu':'i386', 'release':'5', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
      {'reference':'openssh-clients-4.3p2-36.el5', 'cpu':'ppc', 'release':'5', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
      {'reference':'openssh-clients-4.3p2-36.el5', 'cpu':'s390x', 'release':'5', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
      {'reference':'openssh-clients-4.3p2-36.el5', 'cpu':'x86_64', 'release':'5', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
      {'reference':'openssh-server-4.3p2-36.el5', 'cpu':'i386', 'release':'5', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
      {'reference':'openssh-server-4.3p2-36.el5', 'cpu':'ppc', 'release':'5', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
      {'reference':'openssh-server-4.3p2-36.el5', 'cpu':'s390x', 'release':'5', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE},
      {'reference':'openssh-server-4.3p2-36.el5', 'cpu':'x86_64', 'release':'5', 'rpm_spec_vers_cmp':TRUE, 'allowmaj':TRUE}
    ]
  }
];

var applicable_repo_urls = rhel_determine_applicable_repository_urls(constraints:constraints);
if(applicable_repo_urls == RHEL_REPOS_NO_OVERLAP_MESSAGE) exit(0, RHEL_REPO_NOT_ENABLED);

var flag = 0;
foreach var constraint_array ( constraints ) {
  var repo_relative_urls = NULL;
  if (!empty_or_null(constraint_array['repo_relative_urls'])) repo_relative_urls = constraint_array['repo_relative_urls'];
  foreach var pkg ( constraint_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;
    var cves = NULL;
    if (!empty_or_null(pkg['reference'])) reference = pkg['reference'];
    if (!empty_or_null(pkg['release'])) _release = 'RHEL' + pkg['release'];
    if (!empty_or_null(pkg['sp'])) sp = pkg['sp'];
    if (!empty_or_null(pkg['cpu'])) _cpu = pkg['cpu'];
    if (!empty_or_null(pkg['el_string'])) el_string = pkg['el_string'];
    if (!empty_or_null(pkg['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = pkg['rpm_spec_vers_cmp'];
    if (!empty_or_null(pkg['epoch'])) epoch = pkg['epoch'];
    if (!empty_or_null(pkg['allowmaj'])) allowmaj = pkg['allowmaj'];
    if (!empty_or_null(pkg['exists_check'])) exists_check = pkg['exists_check'];
    if (!empty_or_null(pkg['cves'])) cves = pkg['cves'];
    if (reference &&
        _release &&
        rhel_decide_repo_relative_url_check(required_repo_url_list:repo_relative_urls) &&
        (applicable_repo_urls || (!exists_check || rpm_exists(release:_release, rpm:exists_check))) &&
        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, cves:cves)) flag++;
  }
}

if (flag)
{
  var extra = NULL;
  if (isnull(applicable_repo_urls) || !applicable_repo_urls) extra = rpm_report_get() + redhat_report_repo_caveat();
  else extra = rpm_report_get();
  security_report_v4(
      port       : 0,
      severity   : SECURITY_NOTE,
      extra      : extra
  );
  exit(0);
}
else
{
  var tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'openssh / openssh-askpass / openssh-clients / openssh-server');
}