6.9 Medium
CVSS2
Attack Vector
LOCAL
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:L/AC:M/Au:N/C:C/I:C/A:C
7.8 High
CVSS3
Attack Vector
LOCAL
Attack Complexity
HIGH
Privileges Required
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
0.001 Low
EPSS
Percentile
26.7%
Multiple vulnerabilities have been discovered in the Xen hypervisor :
CVE-2017-17563 Jan Beulich discovered that an incorrect reference count overflow check in x86 shadow mode may result in denial of service or privilege escalation.
CVE-2017-17564 Jan Beulich discovered that improper x86 shadow mode reference count error handling may result in denial of service or privilege escalation.
CVE-2017-17565 Jan Beulich discovered that an incomplete bug check in x86 log-dirty handling may result in denial of service.
CVE-2017-17566 Jan Beulich discovered that x86 PV guests may gain access to internally used pages which could result in denial of service or potential privilege escalation.
In addition this update ships the ‘Comet’ shim to address the Meltdown class of vulnerabilities for guests with legacy PV kernels. In addition, the package provides the ‘Xen PTI stage 1’ mitigation which is built-in and enabled by default on Intel systems, but can be disabled with `xpti=false’ on the hypervisor command line (It does not make sense to use both xpti and the Comet shim.)
Please refer to the following URL for more details on how to configure individual mitigation strategies:
https://xenbits.xen.org/xsa/advisory-254.html
Additional information can also be found in README.pti and README.comet.
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Debian Security Advisory DSA-4112. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#
include("compat.inc");
if (description)
{
script_id(106820);
script_version("3.3");
script_cvs_date("Date: 2018/11/13 12:30:46");
script_cve_id("CVE-2017-17563", "CVE-2017-17564", "CVE-2017-17565", "CVE-2017-17566");
script_xref(name:"DSA", value:"4112");
script_name(english:"Debian DSA-4112-1 : xen - security update");
script_summary(english:"Checks dpkg output for the updated package");
script_set_attribute(
attribute:"synopsis",
value:"The remote Debian host is missing a security-related update."
);
script_set_attribute(
attribute:"description",
value:
"Multiple vulnerabilities have been discovered in the Xen hypervisor :
- CVE-2017-17563
Jan Beulich discovered that an incorrect reference count
overflow check in x86 shadow mode may result in denial
of service or privilege escalation.
- CVE-2017-17564
Jan Beulich discovered that improper x86 shadow mode
reference count error handling may result in denial of
service or privilege escalation.
- CVE-2017-17565
Jan Beulich discovered that an incomplete bug check in
x86 log-dirty handling may result in denial of service.
- CVE-2017-17566
Jan Beulich discovered that x86 PV guests may gain
access to internally used pages which could result in
denial of service or potential privilege escalation.
In addition this update ships the 'Comet' shim to address the Meltdown
class of vulnerabilities for guests with legacy PV kernels. In
addition, the package provides the 'Xen PTI stage 1' mitigation which
is built-in and enabled by default on Intel systems, but can be
disabled with `xpti=false' on the hypervisor command line (It does not
make sense to use both xpti and the Comet shim.)
Please refer to the following URL for more details on how to configure
individual mitigation strategies:
https://xenbits.xen.org/xsa/advisory-254.html
Additional information can also be found in README.pti and
README.comet."
);
script_set_attribute(
attribute:"see_also",
value:"https://security-tracker.debian.org/tracker/CVE-2017-17563"
);
script_set_attribute(
attribute:"see_also",
value:"https://security-tracker.debian.org/tracker/CVE-2017-17564"
);
script_set_attribute(
attribute:"see_also",
value:"https://security-tracker.debian.org/tracker/CVE-2017-17565"
);
script_set_attribute(
attribute:"see_also",
value:"https://security-tracker.debian.org/tracker/CVE-2017-17566"
);
script_set_attribute(
attribute:"see_also",
value:"https://xenbits.xen.org/xsa/advisory-254.html"
);
script_set_attribute(
attribute:"see_also",
value:"https://security-tracker.debian.org/tracker/source-package/xen"
);
script_set_attribute(
attribute:"see_also",
value:"https://packages.debian.org/source/stretch/xen"
);
script_set_attribute(
attribute:"see_also",
value:"https://www.debian.org/security/2018/dsa-4112"
);
script_set_attribute(
attribute:"solution",
value:
"Upgrade the xen packages.
For the stable distribution (stretch), these problems have been fixed
in version 4.8.3+comet2+shim4.10.0+comet3-1+deb9u4.1."
);
script_set_cvss_base_vector("CVSS2#AV:L/AC:M/Au:N/C:C/I:C/A:C");
script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:H/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:debian:debian_linux:xen");
script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:9.0");
script_set_attribute(attribute:"patch_publication_date", value:"2018/02/14");
script_set_attribute(attribute:"plugin_publication_date", value:"2018/02/15");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_copyright(english:"This script is Copyright (C) 2018 and is owned by Tenable, Inc. or an Affiliate thereof.");
script_family(english:"Debian Local Security Checks");
script_dependencies("ssh_get_info.nasl");
script_require_keys("Host/local_checks_enabled", "Host/Debian/release", "Host/Debian/dpkg-l");
exit(0);
}
include("audit.inc");
include("debian_package.inc");
if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item("Host/Debian/release")) audit(AUDIT_OS_NOT, "Debian");
if (!get_kb_item("Host/Debian/dpkg-l")) audit(AUDIT_PACKAGE_LIST_MISSING);
flag = 0;
if (deb_check(release:"9.0", prefix:"libxen-4.8", reference:"4.8.3+comet2+shim4.10.0+comet3-1+deb9u4.1")) flag++;
if (deb_check(release:"9.0", prefix:"libxen-dev", reference:"4.8.3+comet2+shim4.10.0+comet3-1+deb9u4.1")) flag++;
if (deb_check(release:"9.0", prefix:"libxenstore3.0", reference:"4.8.3+comet2+shim4.10.0+comet3-1+deb9u4.1")) flag++;
if (deb_check(release:"9.0", prefix:"xen-hypervisor-4.8-amd64", reference:"4.8.3+comet2+shim4.10.0+comet3-1+deb9u4.1")) flag++;
if (deb_check(release:"9.0", prefix:"xen-hypervisor-4.8-arm64", reference:"4.8.3+comet2+shim4.10.0+comet3-1+deb9u4.1")) flag++;
if (deb_check(release:"9.0", prefix:"xen-hypervisor-4.8-armhf", reference:"4.8.3+comet2+shim4.10.0+comet3-1+deb9u4.1")) flag++;
if (deb_check(release:"9.0", prefix:"xen-system-amd64", reference:"4.8.3+comet2+shim4.10.0+comet3-1+deb9u4.1")) flag++;
if (deb_check(release:"9.0", prefix:"xen-system-arm64", reference:"4.8.3+comet2+shim4.10.0+comet3-1+deb9u4.1")) flag++;
if (deb_check(release:"9.0", prefix:"xen-system-armhf", reference:"4.8.3+comet2+shim4.10.0+comet3-1+deb9u4.1")) flag++;
if (deb_check(release:"9.0", prefix:"xen-utils-4.8", reference:"4.8.3+comet2+shim4.10.0+comet3-1+deb9u4.1")) flag++;
if (deb_check(release:"9.0", prefix:"xen-utils-common", reference:"4.8.3+comet2+shim4.10.0+comet3-1+deb9u4.1")) flag++;
if (deb_check(release:"9.0", prefix:"xenstore-utils", reference:"4.8.3+comet2+shim4.10.0+comet3-1+deb9u4.1")) flag++;
if (flag)
{
if (report_verbosity > 0) security_warning(port:0, extra:deb_report_get());
else security_warning(0);
exit(0);
}
else audit(AUDIT_HOST_NOT, "affected");
Vendor | Product | Version | CPE |
---|---|---|---|
debian | debian_linux | xen | p-cpe:/a:debian:debian_linux:xen |
debian | debian_linux | 9.0 | cpe:/o:debian:debian_linux:9.0 |
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-17563
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-17564
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-17565
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-17566
packages.debian.org/source/stretch/xen
security-tracker.debian.org/tracker/CVE-2017-17563
security-tracker.debian.org/tracker/CVE-2017-17564
security-tracker.debian.org/tracker/CVE-2017-17565
security-tracker.debian.org/tracker/CVE-2017-17566
security-tracker.debian.org/tracker/source-package/xen
www.debian.org/security/2018/dsa-4112
xenbits.xen.org/xsa/advisory-254.html
6.9 Medium
CVSS2
Attack Vector
LOCAL
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:L/AC:M/Au:N/C:C/I:C/A:C
7.8 High
CVSS3
Attack Vector
LOCAL
Attack Complexity
HIGH
Privileges Required
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
0.001 Low
EPSS
Percentile
26.7%