Oracle Linux 7 : bash (ELSA-2017-1931)

2017-08-09T00:00:00
ID ORACLELINUX_ELSA-2017-1931.NASL
Type nessus
Reporter This script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
Modified 2020-04-02T00:00:00

Description

From Red Hat Security Advisory 2017:1931 :

An update for bash 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 bash packages provide Bash (Bourne-again shell), which is the default shell for Red Hat Enterprise Linux.

Security Fix(es) :

  • An arbitrary command injection flaw was found in the way bash processed the hostname value. A malicious DHCP server could use this flaw to execute arbitrary commands on the DHCP client machines running bash under specific circumstances. (CVE-2016-0634)

  • An arbitrary command injection flaw was found in the way bash processed the SHELLOPTS and PS4 environment variables. A local, authenticated attacker could use this flaw to exploit poorly written setuid programs to elevate their privileges under certain circumstances. (CVE-2016-7543)

  • A denial of service flaw was found in the way bash handled popd commands. A poorly written shell script could cause bash to crash resulting in a local denial of service limited to a specific bash session. (CVE-2016-9401)

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.

                                        
                                            #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Red Hat Security Advisory RHSA-2017:1931 and 
# Oracle Linux Security Advisory ELSA-2017-1931 respectively.
#

include("compat.inc");

if (description)
{
  script_id(102289);
  script_version("3.4");
  script_cvs_date("Date: 2019/09/27 13:00:38");

  script_cve_id("CVE-2016-0634", "CVE-2016-7543", "CVE-2016-9401");
  script_xref(name:"RHSA", value:"2017:1931");

  script_name(english:"Oracle Linux 7 : bash (ELSA-2017-1931)");
  script_summary(english:"Checks rpm output for the updated packages");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote Oracle Linux host is missing one or more security updates."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"From Red Hat Security Advisory 2017:1931 :

An update for bash 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 bash packages provide Bash (Bourne-again shell), which is the
default shell for Red Hat Enterprise Linux.

Security Fix(es) :

* An arbitrary command injection flaw was found in the way bash
processed the hostname value. A malicious DHCP server could use this
flaw to execute arbitrary commands on the DHCP client machines running
bash under specific circumstances. (CVE-2016-0634)

* An arbitrary command injection flaw was found in the way bash
processed the SHELLOPTS and PS4 environment variables. A local,
authenticated attacker could use this flaw to exploit poorly written
setuid programs to elevate their privileges under certain
circumstances. (CVE-2016-7543)

* A denial of service flaw was found in the way bash handled popd
commands. A poorly written shell script could cause bash to crash
resulting in a local denial of service limited to a specific bash
session. (CVE-2016-9401)

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."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://oss.oracle.com/pipermail/el-errata/2017-August/007079.html"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected bash 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_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:N/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:"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:oracle:linux:bash");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:bash-doc");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:oracle:linux:7");

  script_set_attribute(attribute:"vuln_publication_date", value:"2017/01/19");
  script_set_attribute(attribute:"patch_publication_date", value:"2017/08/08");
  script_set_attribute(attribute:"plugin_publication_date", value:"2017/08/09");
  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:"Oracle Linux Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/OracleLinux", "Host/RedHat/release", "Host/RedHat/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);
if (!get_kb_item("Host/OracleLinux")) audit(AUDIT_OS_NOT, "Oracle Linux");
release = get_kb_item("Host/RedHat/release");
if (isnull(release) || !pregmatch(pattern: "Oracle (?:Linux Server|Enterprise Linux)", string:release)) audit(AUDIT_OS_NOT, "Oracle Linux");
os_ver = pregmatch(pattern: "Oracle (?:Linux Server|Enterprise Linux) .*release ([0-9]+(\.[0-9]+)?)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Oracle Linux");
os_ver = os_ver[1];
if (! preg(pattern:"^7([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Oracle Linux 7", "Oracle Linux " + 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$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "Oracle Linux", cpu);
if ("x86_64" >!< cpu) audit(AUDIT_ARCH_NOT, "x86_64", cpu);

flag = 0;
if (rpm_check(release:"EL7", cpu:"x86_64", reference:"bash-4.2.46-28.el7")) flag++;
if (rpm_check(release:"EL7", cpu:"x86_64", reference:"bash-doc-4.2.46-28.el7")) flag++;


if (flag)
{
  if (report_verbosity > 0) security_hole(port:0, extra:rpm_report_get());
  else security_hole(0);
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "bash / bash-doc");
}