6.1 Medium
CVSS2
Attack Vector
LOCAL
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
COMPLETE
AV:L/AC:L/Au:N/C:P/I:P/A:C
8.8 High
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
0.001 Low
EPSS
Percentile
26.7%
update Xen page-table isolation (XPTI) mitigation and add Branch Target Injection (BTI) mitigation for XSA-254 DoS via non-preemptable L3/L4 pagetable freeing [XSA-252] (#1549568) grant table v2 -> v1 transition may crash Xen [XSA-255] (#1549570) x86 PVH guest without LAPIC may DoS the host [XSA-256] (#1549572)
Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website.
Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Fedora Security Advisory FEDORA-2018-0746dac335.
#
include('deprecated_nasl_level.inc');
include('compat.inc');
if (description)
{
script_id(108492);
script_version("1.4");
script_set_attribute(attribute:"plugin_modification_date", value:"2021/01/06");
script_cve_id("CVE-2018-7540", "CVE-2018-7541", "CVE-2018-7542");
script_xref(name:"FEDORA", value:"2018-0746dac335");
script_name(english:"Fedora 26 : xen (2018-0746dac335)");
script_summary(english:"Checks rpm output for the updated package.");
script_set_attribute(
attribute:"synopsis",
value:"The remote Fedora host is missing a security update."
);
script_set_attribute(
attribute:"description",
value:
"update Xen page-table isolation (XPTI) mitigation and add Branch
Target Injection (BTI) mitigation for XSA-254 DoS via non-preemptable
L3/L4 pagetable freeing [XSA-252] (#1549568) grant table v2 -> v1
transition may crash Xen [XSA-255] (#1549570) x86 PVH guest without
LAPIC may DoS the host [XSA-256] (#1549572)
Note that Tenable Network Security has extracted the preceding
description block directly from the Fedora update system website.
Tenable has attempted to automatically clean and format it as much as
possible without introducing additional issues."
);
script_set_attribute(
attribute:"see_also",
value:"https://bodhi.fedoraproject.org/updates/FEDORA-2018-0746dac335"
);
script_set_attribute(attribute:"solution", value:"Update the affected xen package.");
script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:P/I:P/A:C");
script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fedoraproject:fedora:xen");
script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:26");
script_set_attribute(attribute:"vuln_publication_date", value:"2018/02/27");
script_set_attribute(attribute:"patch_publication_date", value:"2018/03/20");
script_set_attribute(attribute:"plugin_publication_date", value:"2018/03/21");
script_set_attribute(attribute:"generated_plugin", value:"current");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_copyright(english:"This script is Copyright (C) 2018-2021 and is owned by Tenable, Inc. or an Affiliate thereof.");
script_family(english:"Fedora Local Security Checks");
script_dependencies("ssh_get_info.nasl");
script_require_keys("Host/local_checks_enabled", "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);
release = get_kb_item("Host/RedHat/release");
if (isnull(release) || "Fedora" >!< release) audit(AUDIT_OS_NOT, "Fedora");
os_ver = pregmatch(pattern: "Fedora.*release ([0-9]+)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Fedora");
os_ver = os_ver[1];
if (! preg(pattern:"^26([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Fedora 26", "Fedora " + os_ver);
if (!get_kb_item("Host/RedHat/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);
cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "Fedora", cpu);
flag = 0;
if (rpm_check(release:"FC26", reference:"xen-4.8.3-3.fc26")) 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, "xen");
}
Vendor | Product | Version | CPE |
---|---|---|---|
fedoraproject | fedora | xen | p-cpe:/a:fedoraproject:fedora:xen |
fedoraproject | fedora | 26 | cpe:/o:fedoraproject:fedora:26 |
6.1 Medium
CVSS2
Attack Vector
LOCAL
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
COMPLETE
AV:L/AC:L/Au:N/C:P/I:P/A:C
8.8 High
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
0.001 Low
EPSS
Percentile
26.7%