CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
SINGLE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:L/Au:S/C:N/I:N/A:P
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS
Percentile
93.7%
Updated krb5 packages that fix two security issues are now available for Red Hat Enterprise Linux 6.
Red Hat Product Security has rated this update as having Moderate security impact. Common Vulnerability Scoring System (CVSS) base scores, which give detailed severity ratings, are available for each vulnerability from the CVE links in the References section.
Kerberos is a networked authentication system which allows clients and servers to authenticate to each other with the help of a trusted third party, the Kerberos KDC.
A memory leak flaw was found in the krb5_unparse_name() function of the MIT Kerberos kadmind service. An authenticated attacker could repeatedly send specially crafted requests to the server, which could cause the server to consume large amounts of memory resources, ultimately leading to a denial of service due to memory exhaustion.
(CVE-2015-8631)
An out-of-bounds read flaw was found in the kadmind service of MIT Kerberos. An authenticated attacker could send a maliciously crafted message to force kadmind to read beyond the end of allocated memory, and write the memory contents to the KDC database if the attacker has write permission, leading to information disclosure. (CVE-2015-8629)
The CVE-2015-8631 issue was discovered by Simo Sorce of Red Hat.
All krb5 users are advised to upgrade to these updated packages, which contain backported patches to correct these issues. After installing the updated packages, running Kerberos services (krb5kdc, kadmin, and kprop) will be restarted automatically.
#%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-2016:0493 and
# CentOS Errata and Security Advisory 2016:0493 respectively.
#
include('deprecated_nasl_level.inc');
include('compat.inc');
if (description)
{
script_id(90122);
script_version("2.9");
script_set_attribute(attribute:"plugin_modification_date", value:"2021/01/04");
script_cve_id("CVE-2015-8629", "CVE-2015-8631");
script_xref(name:"RHSA", value:"2016:0493");
script_name(english:"CentOS 6 : krb5 (CESA-2016:0493)");
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:
"Updated krb5 packages that fix two security issues are now available
for Red Hat Enterprise Linux 6.
Red Hat Product Security has rated this update as having Moderate
security impact. Common Vulnerability Scoring System (CVSS) base
scores, which give detailed severity ratings, are available for each
vulnerability from the CVE links in the References section.
Kerberos is a networked authentication system which allows clients and
servers to authenticate to each other with the help of a trusted third
party, the Kerberos KDC.
A memory leak flaw was found in the krb5_unparse_name() function of
the MIT Kerberos kadmind service. An authenticated attacker could
repeatedly send specially crafted requests to the server, which could
cause the server to consume large amounts of memory resources,
ultimately leading to a denial of service due to memory exhaustion.
(CVE-2015-8631)
An out-of-bounds read flaw was found in the kadmind service of MIT
Kerberos. An authenticated attacker could send a maliciously crafted
message to force kadmind to read beyond the end of allocated memory,
and write the memory contents to the KDC database if the attacker has
write permission, leading to information disclosure. (CVE-2015-8629)
The CVE-2015-8631 issue was discovered by Simo Sorce of Red Hat.
All krb5 users are advised to upgrade to these updated packages, which
contain backported patches to correct these issues. After installing
the updated packages, running Kerberos services (krb5kdc, kadmin, and
kprop) will be restarted automatically."
);
# https://lists.centos.org/pipermail/centos-announce/2016-March/021767.html
script_set_attribute(
attribute:"see_also",
value:"http://www.nessus.org/u?7a0bfa1a"
);
script_set_attribute(attribute:"solution", value:"Update the affected krb5 packages.");
script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:N/I:N/A:C");
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:L/UI:N/S:U/C:N/I:N/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-2015-8631");
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:krb5-devel");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:krb5-libs");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:krb5-pkinit-openssl");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:krb5-server");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:krb5-server-ldap");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:krb5-workstation");
script_set_attribute(attribute:"cpe", value:"cpe:/o:centos:centos:6");
script_set_attribute(attribute:"vuln_publication_date", value:"2016/02/13");
script_set_attribute(attribute:"patch_publication_date", value:"2016/03/23");
script_set_attribute(attribute:"plugin_publication_date", value:"2016/03/24");
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:"^6([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "CentOS 6.x", "CentOS " + os_ver);
if (!get_kb_item("Host/CentOS/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);
cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "CentOS", cpu);
flag = 0;
if (rpm_check(release:"CentOS-6", reference:"krb5-devel-1.10.3-42z1.el6_7")) flag++;
if (rpm_check(release:"CentOS-6", reference:"krb5-libs-1.10.3-42z1.el6_7")) flag++;
if (rpm_check(release:"CentOS-6", reference:"krb5-pkinit-openssl-1.10.3-42z1.el6_7")) flag++;
if (rpm_check(release:"CentOS-6", reference:"krb5-server-1.10.3-42z1.el6_7")) flag++;
if (rpm_check(release:"CentOS-6", reference:"krb5-server-ldap-1.10.3-42z1.el6_7")) flag++;
if (rpm_check(release:"CentOS-6", reference:"krb5-workstation-1.10.3-42z1.el6_7")) flag++;
if (flag)
{
security_report_v4(
port : 0,
severity : SECURITY_WARNING,
extra : rpm_report_get()
);
exit(0);
}
else
{
tested = pkg_tests_get();
if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
else audit(AUDIT_PACKAGE_NOT_INSTALLED, "krb5-devel / krb5-libs / krb5-pkinit-openssl / krb5-server / etc");
}
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
SINGLE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:L/Au:S/C:N/I:N/A:P
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS
Percentile
93.7%