RHEL 7 : gdm and gnome-session (RHSA-2017:2128)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Red Hat Security Advisory RHSA-2017:2128. The text 
# itself is copyright (C) Red Hat, Inc.
#

include("compat.inc");

if (description)
{
  script_id(102113);
  script_version("3.11");
  script_cvs_date("Date: 2019/10/24 15:35:43");

  script_cve_id("CVE-2015-7496");
  script_xref(name:"RHSA", value:"2017:2128");

  script_name(english:"RHEL 7 : gdm and gnome-session (RHSA-2017:2128)");
  script_summary(english:"Checks the rpm output for the updated packages");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote Red Hat host is missing one or more security updates."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"An update for gdm and gnome-session is now available for Red Hat
Enterprise Linux 7.

Red Hat Product Security has rated this update as having a security
impact of Moderate. A Common Vulnerability Scoring System (CVSS) base
score, which gives a detailed severity rating, is available for each
vulnerability from the CVE link(s) in the References section.

The GNOME Display Manager (GDM) provides the graphical login screen
shown shortly after boot up, log out, and when user-switching.

The following packages have been upgraded to a later upstream version:
gdm (3.22.3), gnome-session (3.22.3). (BZ#1386862, BZ#1386957)

Security Fix(es) :

* It was found that gdm could crash due to a signal handler dispatched
to an invalid conversation. An attacker could crash gdm by holding the
escape key when the screen is locked, possibly bypassing the locked
screen. (CVE-2015-7496)

Additional Changes :

For detailed information on changes in this release, see the Red Hat
Enterprise Linux 7.4 Release Notes linked from the References section."
  );
  # https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?3395ff0b"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/errata/RHSA-2017:2128"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2015-7496"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gdm");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gdm-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gdm-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gnome-session");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gnome-session-custom-session");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gnome-session-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gnome-session-xsession");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:7");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:7.4");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:7.5");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:7.6");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:7.7");

  script_set_attribute(attribute:"vuln_publication_date", value:"2015/11/24");
  script_set_attribute(attribute:"patch_publication_date", value:"2017/08/01");
  script_set_attribute(attribute:"plugin_publication_date", value:"2017/08/02");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"Red Hat Local Security Checks");

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

  exit(0);
}


include("audit.inc");
include("global_settings.inc");
include("misc_func.inc");
include("rpm.inc");

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item("Host/RedHat/release");
if (isnull(release) || "Red Hat" >!< release) audit(AUDIT_OS_NOT, "Red Hat");
os_ver = pregmatch(pattern: "Red Hat Enterprise Linux.*release ([0-9]+(\.[0-9]+)?)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Red Hat");
os_ver = os_ver[1];
if (! preg(pattern:"^7([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Red Hat 7.x", "Red Hat " + os_ver);

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

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

yum_updateinfo = get_kb_item("Host/RedHat/yum-updateinfo");
if (!empty_or_null(yum_updateinfo)) 
{
  rhsa = "RHSA-2017:2128";
  yum_report = redhat_generate_yum_updateinfo_report(rhsa:rhsa);
  if (!empty_or_null(yum_report))
  {
    security_report_v4(
      port       : 0,
      severity   : SECURITY_HOLE,
      extra      : yum_report 
    );
    exit(0);
  }
  else
  {
    audit_message = "affected by Red Hat security advisory " + rhsa;
    audit(AUDIT_OS_NOT, audit_message);
  }
}
else
{
  flag = 0;
  if (rpm_check(release:"RHEL7", reference:"gdm-3.22.3-11.el7")) flag++;

  if (rpm_check(release:"RHEL7", reference:"gdm-debuginfo-3.22.3-11.el7")) flag++;

  if (rpm_check(release:"RHEL7", reference:"gdm-devel-3.22.3-11.el7")) flag++;

  if (rpm_check(release:"RHEL7", cpu:"s390x", reference:"gnome-session-3.22.3-4.el7")) flag++;

  if (rpm_check(release:"RHEL7", cpu:"x86_64", reference:"gnome-session-3.22.3-4.el7")) flag++;

  if (rpm_check(release:"RHEL7", cpu:"s390x", reference:"gnome-session-custom-session-3.22.3-4.el7")) flag++;

  if (rpm_check(release:"RHEL7", cpu:"x86_64", reference:"gnome-session-custom-session-3.22.3-4.el7")) flag++;

  if (rpm_check(release:"RHEL7", cpu:"s390x", reference:"gnome-session-debuginfo-3.22.3-4.el7")) flag++;

  if (rpm_check(release:"RHEL7", cpu:"x86_64", reference:"gnome-session-debuginfo-3.22.3-4.el7")) flag++;

  if (rpm_check(release:"RHEL7", cpu:"s390x", reference:"gnome-session-xsession-3.22.3-4.el7")) flag++;

  if (rpm_check(release:"RHEL7", cpu:"x86_64", reference:"gnome-session-xsession-3.22.3-4.el7")) flag++;


  if (flag)
  {
    security_report_v4(
      port       : 0,
      severity   : SECURITY_HOLE,
      extra      : rpm_report_get() + redhat_report_package_caveat()
    );
    exit(0);
  }
  else
  {
    tested = pkg_tests_get();
    if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
    else audit(AUDIT_PACKAGE_NOT_INSTALLED, "gdm / gdm-debuginfo / gdm-devel / gnome-session / etc");
  }
}