CentOS 7 : sudo (CESA-2016:2593)

#%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-2016:2593 and 
# CentOS Errata and Security Advisory 2016:2593 respectively.
#

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

if (description)
{
  script_id(95339);
  script_version("3.8");
  script_set_attribute(attribute:"plugin_modification_date", value:"2021/01/04");

  script_cve_id("CVE-2016-7091");
  script_xref(name:"RHSA", value:"2016:2593");

  script_name(english:"CentOS 7 : sudo (CESA-2016:2593)");
  script_summary(english:"Checks rpm output for the updated packages");

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

Red Hat Product Security has rated this update as having a security
impact of Low. 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 sudo packages contain the sudo utility which allows system
administrators to provide certain users with the permission to execute
privileged commands, which are used for system management purposes,
without having to log in as root.

Security Fix(es) :

* It was discovered that the default sudo configuration preserved the
value of INPUTRC from the user's environment, which could lead to
information disclosure. A local user with sudo access to a restricted
program that uses readline could use this flaw to read content from
specially formatted files with elevated privileges provided by sudo.
(CVE-2016-7091)

Note: With this update, INPUTRC was removed from the env_keep list in
/etc/ sudoers to avoid having sudo preserve the value of this variable
when invoking privileged commands.

Red Hat would like to thank Grisha Levit for reporting this issue.

Additional Changes :

For detailed information on changes in this release, see the Red Hat
Enterprise Linux 7.3 Release Notes linked from the References section."
  );
  # https://lists.centos.org/pipermail/centos-cr-announce/2016-November/003522.html
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?9415807b"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected sudo packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:C/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:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2016-7091");
  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:centos:centos:sudo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:sudo-devel");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:centos:centos:7");

  script_set_attribute(attribute:"vuln_publication_date", value:"2016/12/22");
  script_set_attribute(attribute:"patch_publication_date", value:"2016/11/25");
  script_set_attribute(attribute:"plugin_publication_date", value:"2016/11/28");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2016-2021 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"CentOS Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/CentOS/release", "Host/CentOS/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/CentOS/release");
if (isnull(release) || "CentOS" >!< release) audit(AUDIT_OS_NOT, "CentOS");
os_ver = pregmatch(pattern: "CentOS(?: Linux)? release ([0-9]+)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "CentOS");
os_ver = os_ver[1];
if (! preg(pattern:"^7([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "CentOS 7.x", "CentOS " + os_ver);

if (!get_kb_item("Host/CentOS/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$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "CentOS", cpu);


flag = 0;
if (rpm_check(release:"CentOS-7", cpu:"x86_64", reference:"sudo-1.8.6p7-20.el7")) flag++;
if (rpm_check(release:"CentOS-7", cpu:"x86_64", reference:"sudo-devel-1.8.6p7-20.el7")) flag++;


if (flag)
{
  cr_plugin_caveat = '\n' +
    'NOTE: The security advisory associated with this vulnerability has a\n' +
    'fixed package version that may only be available in the continuous\n' +
    'release (CR) repository for CentOS, until it is present in the next\n' +
    'point release of CentOS.\n\n' +

    'If an equal or higher package level does not exist in the baseline\n' +
    'repository for your major version of CentOS, then updates from the CR\n' +
    'repository will need to be applied in order to address the\n' +
    'vulnerability.\n';
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : rpm_report_get() + cr_plugin_caveat
  );
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "sudo / sudo-devel");
}