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.
#%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-2017:1931 and
# CentOS Errata and Security Advisory 2017:1931 respectively.
#
include('deprecated_nasl_level.inc');
include('compat.inc');
if (description)
{
script_id(102744);
script_version("3.7");
script_set_attribute(attribute:"plugin_modification_date", value:"2021/01/04");
script_cve_id("CVE-2016-0634", "CVE-2016-7543", "CVE-2016-9401");
script_xref(name:"RHSA", value:"2017:1931");
script_name(english:"CentOS 7 : bash (CESA-2017:1931)");
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 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."
);
# https://lists.centos.org/pipermail/centos-cr-announce/2017-August/004011.html
script_set_attribute(
attribute:"see_also",
value:"http://www.nessus.org/u?0850f672"
);
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:"cvss_score_source", value:"CVE-2016-7543");
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:bash");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:bash-doc");
script_set_attribute(attribute:"cpe", value:"cpe:/o:centos:centos:7");
script_set_attribute(attribute:"vuln_publication_date", value:"2017/01/19");
script_set_attribute(attribute:"patch_publication_date", value:"2017/08/23");
script_set_attribute(attribute:"plugin_publication_date", value:"2017/08/25");
script_set_attribute(attribute:"generated_plugin", value:"current");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_copyright(english:"This script is Copyright (C) 2017-2021 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:"bash-4.2.46-28.el7")) flag++;
if (rpm_check(release:"CentOS-7", cpu:"x86_64", reference:"bash-doc-4.2.46-28.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_HOLE,
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, "bash / bash-doc");
}