Debian DLA-614-1 : xen security update

2016-09-12T00:00:00
ID DEBIAN_DLA-614.NASL
Type nessus
Reporter Tenable
Modified 2018-07-13T00:00:00

Description

Multiple vulnerabilities have been discovered in the Xen hypervisor. The Common Vulnerabilities and Exposures project identifies the following problems :

CVE-2016-7092 (XSA-185)

Jeremie Boutoille of Quarkslab and Shangcong Luan of Alibaba discovered a flaw in the handling of L3 pagetable entries, allowing a malicious 32-bit PV guest administrator can escalate their privilege to that of the host.

CVE-2016-7094 (XSA-187)

x86 HVM guests running with shadow paging use a subset of the x86 emulator to handle the guest writing to its own pagetables. Andrew Cooper of Citrix discovered that there are situations a guest can provoke which result in exceeding the space allocated for internal state. A malicious HVM guest administrator can cause Xen to fail a bug check, causing a denial of service to the host.

For Debian 7 'Wheezy', these problems have been fixed in version 4.1.6.lts1-2. For Debian 8 'Jessie', these problems have been fixed in version 4.4.1-9+deb8u7.

We recommend that you upgrade your xen packages.

NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

                                        
                                            #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Debian Security Advisory DLA-614-1. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#

include("compat.inc");

if (description)
{
  script_id(93413);
  script_version("2.12");
  script_cvs_date("Date: 2018/07/13 15:23:36");

  script_cve_id("CVE-2016-7092", "CVE-2016-7094");
  script_xref(name:"IAVB", value:"2016-B-0140");

  script_name(english:"Debian DLA-614-1 : xen security update");
  script_summary(english:"Checks dpkg output for the updated packages.");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote Debian host is missing a security update."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"Multiple vulnerabilities have been discovered in the Xen hypervisor.
The Common Vulnerabilities and Exposures project identifies the
following problems :

CVE-2016-7092 (XSA-185)

Jeremie Boutoille of Quarkslab and Shangcong Luan of Alibaba
discovered a flaw in the handling of L3 pagetable entries, allowing a
malicious 32-bit PV guest administrator can escalate their privilege
to that of the host.

CVE-2016-7094 (XSA-187)

x86 HVM guests running with shadow paging use a subset of the x86
emulator to handle the guest writing to its own pagetables. Andrew
Cooper of Citrix discovered that there are situations a guest can
provoke which result in exceeding the space allocated for internal
state. A malicious HVM guest administrator can cause Xen to fail a bug
check, causing a denial of service to the host.

For Debian 7 'Wheezy', these problems have been fixed in version
4.1.6.lts1-2. For Debian 8 'Jessie', these problems have been fixed in
version 4.4.1-9+deb8u7. 

We recommend that you upgrade your xen packages.

NOTE: Tenable Network Security has extracted the preceding description
block directly from the DLA security advisory. 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://lists.debian.org/debian-lts-announce/2016/09/msg00008.html"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://packages.debian.org/source/wheezy/xen"
  );
  script_set_attribute(attribute:"solution", value:"Upgrade the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:S/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:H/UI:N/S:C/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:debian:debian_linux:libxen-4.1");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libxen-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libxen-ocaml");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libxen-ocaml-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libxenstore3.0");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:xen-docs-4.1");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:xen-hypervisor-4.1-amd64");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:xen-hypervisor-4.1-i386");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:xen-system-amd64");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:xen-system-i386");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:xen-utils-4.1");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:xen-utils-common");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:xenstore-utils");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:7.0");

  script_set_attribute(attribute:"patch_publication_date", value:"2016/09/09");
  script_set_attribute(attribute:"plugin_publication_date", value:"2016/09/12");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2016-2018 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:"7.0", prefix:"libxen-4.1", reference:"4.1.6.lts1-2")) flag++;
if (deb_check(release:"7.0", prefix:"libxen-dev", reference:"4.1.6.lts1-2")) flag++;
if (deb_check(release:"7.0", prefix:"libxen-ocaml", reference:"4.1.6.lts1-2")) flag++;
if (deb_check(release:"7.0", prefix:"libxen-ocaml-dev", reference:"4.1.6.lts1-2")) flag++;
if (deb_check(release:"7.0", prefix:"libxenstore3.0", reference:"4.1.6.lts1-2")) flag++;
if (deb_check(release:"7.0", prefix:"xen-docs-4.1", reference:"4.1.6.lts1-2")) flag++;
if (deb_check(release:"7.0", prefix:"xen-hypervisor-4.1-amd64", reference:"4.1.6.lts1-2")) flag++;
if (deb_check(release:"7.0", prefix:"xen-hypervisor-4.1-i386", reference:"4.1.6.lts1-2")) flag++;
if (deb_check(release:"7.0", prefix:"xen-system-amd64", reference:"4.1.6.lts1-2")) flag++;
if (deb_check(release:"7.0", prefix:"xen-system-i386", reference:"4.1.6.lts1-2")) flag++;
if (deb_check(release:"7.0", prefix:"xen-utils-4.1", reference:"4.1.6.lts1-2")) flag++;
if (deb_check(release:"7.0", prefix:"xen-utils-common", reference:"4.1.6.lts1-2")) flag++;
if (deb_check(release:"7.0", prefix:"xenstore-utils", reference:"4.1.6.lts1-2")) 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");