Vulnerabilities > CVE-2017-12855 - Information Exposure vulnerability in XEN

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from SUSE update advisory SUSE-SU-2017:2450-1.
# The text itself is copyright (C) SUSE.
#

include("compat.inc");

if (description)
{
  script_id(103216);
  script_version("3.9");
  script_cvs_date("Date: 2019/09/11 11:22:16");

  script_cve_id("CVE-2017-10664", "CVE-2017-10806", "CVE-2017-11334", "CVE-2017-11434", "CVE-2017-12135", "CVE-2017-12137", "CVE-2017-12855", "CVE-2017-14316", "CVE-2017-14317", "CVE-2017-14319");

  script_name(english:"SUSE SLES11 Security Update : xen (SUSE-SU-2017:2450-1)");
  script_summary(english:"Checks rpm output for the updated packages.");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote SUSE host is missing one or more security updates."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"This update for xen fixes several issues. These security issues were
fixed :

  - CVE-2017-12135: Unbounded recursion in grant table code
    allowed a malicious guest to crash the host or
    potentially escalate privileges/leak information
    (XSA-226, bsc#1051787).

  - CVE-2017-12137: Incorrectly-aligned updates to
    pagetables allowed for privilege escalation (XSA-227,
    bsc#1051788).

  - CVE-2017-11334: The address_space_write_continue
    function in exec.c allowed local guest OS privileged
    users to cause a denial of service (out-of-bounds access
    and guest instance crash) by leveraging use of
    qemu_map_ram_ptr to access guest ram block area
    (bsc#1048920).

  - CVE-2017-11434: The dhcp_decode function in
    slirp/bootp.c allowed local guest OS users to cause a
    denial of service (out-of-bounds read) via a crafted
    DHCP options string (bsc#1049578).

  - CVE-2017-10806: Stack-based buffer overflow in
    hw/usb/redirect.c allowed local guest OS users to cause
    a denial of service via vectors related to logging debug
    messages (bsc#1047675).

  - CVE-2017-10664: qemu-nbd did not ignore SIGPIPE, which
    allowed remote attackers to cause a denial of service
    (daemon crash) by disconnecting during a
    server-to-client reply attempt (bsc#1046637).

  - CVE-2017-12855: Premature clearing of GTF_writing /
    GTF_reading lead to potentially leaking sensitive
    information (XSA-230, bsc#1052686).

  - CVE-2017-14316: Missing bound check in function
    `alloc_heap_pages` for an internal array allowed
    attackers using crafted hypercalls to execute arbitrary
    code within Xen (XSA-231, bsc#1056278)

  - CVE-2017-14317: A race in cxenstored may have cause a
    double-free allowind for DoS of the xenstored daemon
    (XSA-233, bsc#1056281).

  - CVE-2017-14319: An error while handling grant mappings
    allowed malicious or buggy x86 PV guest to escalate its
    privileges or crash the hypervisor (XSA-234,
    bsc#1056282).

The update package also includes non-security fixes. See advisory for
details.

Note that Tenable Network Security has extracted the preceding
description block directly from the SUSE 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://bugzilla.suse.com/show_bug.cgi?id=1027519"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.suse.com/show_bug.cgi?id=1032598"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.suse.com/show_bug.cgi?id=1037413"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.suse.com/show_bug.cgi?id=1046637"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.suse.com/show_bug.cgi?id=1047675"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.suse.com/show_bug.cgi?id=1048920"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.suse.com/show_bug.cgi?id=1049578"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.suse.com/show_bug.cgi?id=1051787"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.suse.com/show_bug.cgi?id=1051788"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.suse.com/show_bug.cgi?id=1052686"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.suse.com/show_bug.cgi?id=1056278"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.suse.com/show_bug.cgi?id=1056281"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.suse.com/show_bug.cgi?id=1056282"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://www.suse.com/security/cve/CVE-2017-10664/"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://www.suse.com/security/cve/CVE-2017-10806/"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://www.suse.com/security/cve/CVE-2017-11334/"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://www.suse.com/security/cve/CVE-2017-11434/"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://www.suse.com/security/cve/CVE-2017-12135/"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://www.suse.com/security/cve/CVE-2017-12137/"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://www.suse.com/security/cve/CVE-2017-12855/"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://www.suse.com/security/cve/CVE-2017-14316/"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://www.suse.com/security/cve/CVE-2017-14317/"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://www.suse.com/security/cve/CVE-2017-14319/"
  );
  # https://www.suse.com/support/update/announcement/2017/suse-su-20172450-1/
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?70bea784"
  );
  script_set_attribute(
    attribute:"solution", 
    value:
"To install this SUSE Security Update use YaST online_update.
Alternatively you can run the command listed for your product :

SUSE Linux Enterprise Software Development Kit 11-SP4:zypper in -t
patch sdksp4-xen-13281=1

SUSE Linux Enterprise Server 11-SP4:zypper in -t patch
slessp4-xen-13281=1

SUSE Linux Enterprise Debuginfo 11-SP4:zypper in -t patch
dbgsp4-xen-13281=1

To bring your system up-to-date, use 'zypper patch'."
  );
  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:L/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:novell:suse_linux:xen");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:suse_linux:xen-doc-html");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:suse_linux:xen-kmp-default");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:suse_linux:xen-kmp-pae");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:suse_linux:xen-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:suse_linux:xen-tools");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:suse_linux:xen-tools-domU");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:novell:suse_linux:11");

  script_set_attribute(attribute:"vuln_publication_date", value:"2017/07/25");
  script_set_attribute(attribute:"patch_publication_date", value:"2017/09/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2017/09/14");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"SuSE Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/cpu", "Host/SuSE/release", "Host/SuSE/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/SuSE/release");
if (isnull(release) || release !~ "^(SLED|SLES)") audit(AUDIT_OS_NOT, "SUSE");
os_ver = pregmatch(pattern: "^(SLE(S|D)\d+)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "SUSE");
os_ver = os_ver[1];
if (! preg(pattern:"^(SLES11)$", string:os_ver)) audit(AUDIT_OS_NOT, "SUSE SLES11", "SUSE " + os_ver);

if (!get_kb_item("Host/SuSE/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);

cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if (cpu !~ "^i[3-6]86$" && "x86_64" >!< cpu && "s390x" >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "SUSE " + os_ver, cpu);
if (cpu >!< "i386|i486|i586|i686|x86_64") audit(AUDIT_ARCH_NOT, "i386 / i486 / i586 / i686 / x86_64", cpu);


sp = get_kb_item("Host/SuSE/patchlevel");
if (isnull(sp)) sp = "0";
if (os_ver == "SLES11" && (! preg(pattern:"^(4)$", string:sp))) audit(AUDIT_OS_NOT, "SLES11 SP4", os_ver + " SP" + sp);


flag = 0;
if (rpm_check(release:"SLES11", sp:"4", cpu:"x86_64", reference:"xen-kmp-default-4.4.4_22_3.0.101_108.7-61.9.2")) flag++;
if (rpm_check(release:"SLES11", sp:"4", cpu:"x86_64", reference:"xen-libs-4.4.4_22-61.9.2")) flag++;
if (rpm_check(release:"SLES11", sp:"4", cpu:"x86_64", reference:"xen-tools-domU-4.4.4_22-61.9.2")) flag++;
if (rpm_check(release:"SLES11", sp:"4", cpu:"x86_64", reference:"xen-4.4.4_22-61.9.2")) flag++;
if (rpm_check(release:"SLES11", sp:"4", cpu:"x86_64", reference:"xen-doc-html-4.4.4_22-61.9.2")) flag++;
if (rpm_check(release:"SLES11", sp:"4", cpu:"x86_64", reference:"xen-libs-32bit-4.4.4_22-61.9.2")) flag++;
if (rpm_check(release:"SLES11", sp:"4", cpu:"x86_64", reference:"xen-tools-4.4.4_22-61.9.2")) flag++;
if (rpm_check(release:"SLES11", sp:"4", cpu:"x86_64", reference:"xen-kmp-pae-4.4.4_22_3.0.101_108.7-61.9.2")) flag++;
if (rpm_check(release:"SLES11", sp:"4", cpu:"i586", reference:"xen-kmp-default-4.4.4_22_3.0.101_108.7-61.9.2")) flag++;
if (rpm_check(release:"SLES11", sp:"4", cpu:"i586", reference:"xen-libs-4.4.4_22-61.9.2")) flag++;
if (rpm_check(release:"SLES11", sp:"4", cpu:"i586", reference:"xen-tools-domU-4.4.4_22-61.9.2")) flag++;
if (rpm_check(release:"SLES11", sp:"4", cpu:"i586", reference:"xen-kmp-pae-4.4.4_22_3.0.101_108.7-61.9.2")) flag++;


if (flag)
{
  if (report_verbosity > 0) security_hole(port:0, extra:rpm_report_get());
  else security_hole(0);
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "xen");
}

#
# (C) Tenable Network Security, Inc.
#
# The package checks in this plugin were extracted from OracleVM
# Security Advisory OVMSA-2017-0148.
#

include("compat.inc");

if (description)
{
  script_id(102906);
  script_version("3.5");
  script_cvs_date("Date: 2019/09/27 13:00:35");

  script_cve_id("CVE-2017-12135", "CVE-2017-12137", "CVE-2017-12855");

  script_name(english:"OracleVM 3.3 : xen (OVMSA-2017-0148)");
  script_summary(english:"Checks the RPM output for the updated packages.");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote OracleVM host is missing one or more security updates."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"The remote OracleVM system is missing necessary patches to address
critical security updates :

  - From: Jan Beulich Subject: gnttab: correct pin status
    fixup for copy Regardless of copy operations only
    setting GNTPIN_hst*, GNTPIN_dev* also need to be taken
    into account when deciding whether to clear
    _GTF_[read,writ]ing. At least for consistency with code
    elsewhere the read part better doesn't use any mask at
    all. This is XSA-230. (CVE-2017-12855)

  - From: Andrew Cooper Subject: grant_table: Default to v1,
    and disallow transitive grants The reference counting
    and locking discipline for transitive grants is broken.
    Their use is therefore declared out of security support.
    This is XSA-226. Transitive grants are expected to be
    unconditionally available with grant table v2. Hiding
    transitive grants alone is an ABI breakage for the
    guest. Modern versions of Linux and the Windows PV
    drivers use grant table v1, but older versions did use
    v2. In principle, disabling gnttab v2 entirely is the
    safer way to cause guests to avoid using transitive
    grants. However, some older guests which defaulted to
    using gnttab v2 don't tolerate falling back from v2 to
    v1 over migrate. This patch introduces a new command
    line option to control grant table behaviour. One
    suboption allows a choice of the maximum grant table
    version Xen will allow the guest to use, and defaults to
    v2. A different suboption independently controls whether
    transitive grants can be used. The default case is:
    gnttab=max_ver:2 To disable gnttab v2 entirely, use:
    gnttab=max_ver:1 To allow gnttab v2 and transitive
    grants, use: gnttab=max_ver:2,transitive

    Conflict: docs/misc/xen-command-line.markdown
    (CVE-2017-12135)

  - Revert wrong fix for xsa226 [bug 26567225]

  - From 3aab881c7331cf93ffd8d2f2dd9adfd18ed4fc99 Mon Sep 17
    00:00:00 2001 From: Andrew Cooper Date: Tue, 20 Jun 2017
    19:18:54 +0100 Subject: [PATCH] x86/grant: Disallow
    misaligned PTEs Pagetable entries must be aligned to
    function correctly. Disallow attempts from the guest to
    have a grant PTE created at a misaligned address, which
    would result in corruption of the L1 table with
    largely-guest-controlled values. This is XSA-227
    (CVE-2017-12137)

  - Prerequisite patch for xsa227-4.5.patch There is no
    macro ASSERT_UNREACHABLE before OVM3.4 which is needed
    by xsa227-4.5.patch This chunk is picked from upstream
    commit cacdb0faaa121ac8f792d5bd34cc6bc7c72d21da
    (CVE-2017-12137)

  - From: Jan Beulich Subject: gnttab: don't use possibly
    unbounded tail calls There is no guarantee that the
    compiler would actually translate them to branches
    instead of calls, so only ones with a known recursion
    limit are okay :

  - __release_grant_for_copy can call itself only once, as
    __acquire_grant_for_copy won't permit use of multi-level
    transitive grants,

  - __acquire_grant_for_copy is fine to call itself with the
    last argument false, as that prevents further recursion,

  - __acquire_grant_for_copy must not call itself to recover
    from an observed change to the active entry's pin count
    This is XSA-226. (CVE-2017-12135)

  - From 69549b08eb9bd3a525c07a97d952673a3d02c76a Mon Sep 17
    00:00:00 2001 From: Annie Li Date: Fri, 7 Jul 2017
    14:36:08 -0400 Subject: [PATCH] xen: increase default
    max grant frames and max maptrack frames Commit
    9dfba034e increase default max grant frames to 128 which
    is still not enough when the guest has more cpus and
    vbd/vif devices, so set it to 256. Also the default max
    maptrack frames needs to be increased accordingly."
  );
  # https://oss.oracle.com/pipermail/oraclevm-errata/2017-August/000774.html
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?e4f463c5"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Update the affected xen / xen-tools 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:L/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:oracle:vm:xen");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:vm:xen-tools");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:oracle:vm_server:3.3");

  script_set_attribute(attribute:"vuln_publication_date", value:"2017/08/15");
  script_set_attribute(attribute:"patch_publication_date", value:"2017/08/31");
  script_set_attribute(attribute:"plugin_publication_date", value:"2017/09/01");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"OracleVM Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/OracleVM/release", "Host/OracleVM/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/OracleVM/release");
if (isnull(release) || "OVS" >!< release) audit(AUDIT_OS_NOT, "OracleVM");
if (! preg(pattern:"^OVS" + "3\.3" + "(\.[0-9]|$)", string:release)) audit(AUDIT_OS_NOT, "OracleVM 3.3", "OracleVM " + release);
if (!get_kb_item("Host/OracleVM/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, "OracleVM", cpu);
if ("x86_64" >!< cpu) audit(AUDIT_ARCH_NOT, "x86_64", cpu);

flag = 0;
if (rpm_check(release:"OVS3.3", reference:"xen-4.3.0-55.el6.186.45")) flag++;
if (rpm_check(release:"OVS3.3", reference:"xen-tools-4.3.0-55.el6.186.45")) flag++;

if (flag)
{
  if (report_verbosity > 0) security_hole(port:0, extra:rpm_report_get());
  else security_hole(0);
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "xen / xen-tools");
}