Vulnerabilities > CVE-2017-7995 - Information Exposure vulnerability in multiple products

047910
CVSS 1.7 - LOW
Attack vector
LOCAL
Attack complexity
LOW
Privileges required
SINGLE
Confidentiality impact
PARTIAL
Integrity impact
NONE
Availability impact
NONE
local
low complexity
xen
suse
novell
CWE-200
nessus
NVD
Published: 2017-05-03
Updated: 2017-05-15

Summary

Xen PV guest before Xen 4.3 checked access permissions to MMIO ranges only after accessing them, allowing host PCI device space memory reads, leading to information disclosure. This is an error in the get_user function. NOTE: the upstream Xen Project considers versions before 4.5.x to be EOL.

Vulnerable Configurations

Part Description Count
OS
Xen
55
OS
Novell
2
Application
Suse
3

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Subverting Environment Variable Values
    The attacker directly or indirectly modifies environment variables used by or controlling the target software. The attacker's goal is to cause the target software to deviate from its expected operation in a manner that benefits the attacker.
  • Footprinting
    An attacker engages in probing and exploration activity to identify constituents and properties of the target. Footprinting is a general term to describe a variety of information gathering techniques, often used by attackers in preparation for some attack. It consists of using tools to learn as much as possible about the composition, configuration, and security mechanisms of the targeted application, system or network. Information that might be collected during a footprinting effort could include open ports, applications and their versions, network topology, and similar information. While footprinting is not intended to be damaging (although certain activities, such as network scans, can sometimes cause disruptions to vulnerable applications inadvertently) it may often pave the way for more damaging attacks.
  • Exploiting Trust in Client (aka Make the Client Invisible)
    An attack of this type exploits a programs' vulnerabilities in client/server communication channel authentication and data integrity. It leverages the implicit trust a server places in the client, or more importantly, that which the server believes is the client. An attacker executes this type of attack by placing themselves in the communication channel between client and server such that communication directly to the server is possible where the server believes it is communicating only with a valid client. There are numerous variations of this type of attack.
  • Browser Fingerprinting
    An attacker carefully crafts small snippets of Java Script to efficiently detect the type of browser the potential victim is using. Many web-based attacks need prior knowledge of the web browser including the version of browser to ensure successful exploitation of a vulnerability. Having this knowledge allows an attacker to target the victim with attacks that specifically exploit known or zero day weaknesses in the type and version of the browser used by the victim. Automating this process via Java Script as a part of the same delivery system used to exploit the browser is considered more efficient as the attacker can supply a browser fingerprinting method and integrate it with exploit code, all contained in Java Script and in response to the same web page request by the browser.
  • Session Credential Falsification through Prediction
    This attack targets predictable session ID in order to gain privileges. The attacker can predict the session ID used during a transaction to perform spoofing and session hijacking.

Nessus

  • NASL familySuSE Local Security Checks
    NASL idSUSE_SU-2017-1146-1.NASL
    descriptionThis update for xen fixes several security issues : - A malicious 64-bit PV guest may be able to access all of system memory, allowing for all of privilege escalation, host crashes, and information leaks by placing a IRET hypercall in the middle of a multicall batch (XSA-213, bsc#1034843) - A malicious pair of guests may be able to access all of system memory, allowing for all of privilege escalation, host crashes, and information leaks because of a missing check when transfering pages via GNTTABOP_transfer (XSA-214, bsc#1034844). - CVE-2017-7718: hw/display/cirrus_vga_rop.h allowed local guest OS privileged users to cause a denial of service (out-of-bounds read and QEMU process crash) via vectors related to copying VGA data via the cirrus_bitblt_rop_fwd_transp_ and cirrus_bitblt_rop_fwd_ functions (bsc#1034994). - CVE-2016-9603: A privileged user within the guest VM could have caused a heap overflow in the device model process, potentially escalating their privileges to that of the device model process (bsc#1028655) 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.
    last seen2020-06-01
    modified2020-06-02
    plugin id99961
    published2017-05-03
    reporterThis script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/99961
    titleSUSE SLES11 Security Update : xen (SUSE-SU-2017:1146-1)
    code
    #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from SUSE update advisory SUSE-SU-2017:1146-1.
# The text itself is copyright (C) SUSE.
#

include("compat.inc");

if (description)
{
  script_id(99961);
  script_version("3.13");
  script_cvs_date("Date: 2019/09/11 11:22:15");

  script_cve_id("CVE-2016-9603", "CVE-2017-7718", "CVE-2017-7980", "CVE-2017-7995");

  script_name(english:"SUSE SLES11 Security Update : xen (SUSE-SU-2017:1146-1)");
  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 security issues :

  - A malicious 64-bit PV guest may be able to access all of
    system memory, allowing for all of privilege escalation,
    host crashes, and information leaks by placing a IRET
    hypercall in the middle of a multicall batch (XSA-213,
    bsc#1034843)

  - A malicious pair of guests may be able to access all of
    system memory, allowing for all of privilege escalation,
    host crashes, and information leaks because of a missing
    check when transfering pages via GNTTABOP_transfer
    (XSA-214, bsc#1034844).

  - CVE-2017-7718: hw/display/cirrus_vga_rop.h allowed local
    guest OS privileged users to cause a denial of service
    (out-of-bounds read and QEMU process crash) via vectors
    related to copying VGA data via the
    cirrus_bitblt_rop_fwd_transp_ and cirrus_bitblt_rop_fwd_
    functions (bsc#1034994).

  - CVE-2016-9603: A privileged user within the guest VM
    could have caused a heap overflow in the device model
    process, potentially escalating their privileges to that
    of the device model process (bsc#1028655)

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=1028655"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.suse.com/show_bug.cgi?id=1033948"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.suse.com/show_bug.cgi?id=1034843"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.suse.com/show_bug.cgi?id=1034844"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.suse.com/show_bug.cgi?id=1034845"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.suse.com/show_bug.cgi?id=1034994"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.suse.com/show_bug.cgi?id=1035483"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://www.suse.com/security/cve/CVE-2016-9603/"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://www.suse.com/security/cve/CVE-2017-7718/"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://www.suse.com/security/cve/CVE-2017-7980/"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://www.suse.com/security/cve/CVE-2017-7995/"
  );
  # https://www.suse.com/support/update/announcement/2017/suse-su-20171146-1/
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?f504077b"
  );
  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 OpenStack Cloud 5:zypper in -t patch sleclo50sp3-xen-13085=1

SUSE Manager Proxy 2.1:zypper in -t patch slemap21-xen-13085=1

SUSE Manager 2.1:zypper in -t patch sleman21-xen-13085=1

SUSE Linux Enterprise Server 11-SP3-LTSS:zypper in -t patch
slessp3-xen-13085=1

SUSE Linux Enterprise Point of Sale 11-SP3:zypper in -t patch
sleposp3-xen-13085=1

To bring your system up-to-date, use 'zypper patch'."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/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:N/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-doc-pdf");
  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:"2017/04/20");
  script_set_attribute(attribute:"patch_publication_date", value:"2017/05/02");
  script_set_attribute(attribute:"plugin_publication_date", value:"2017/05/03");
  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:"^(3)$", string:sp))) audit(AUDIT_OS_NOT, "SLES11 SP3", os_ver + " SP" + sp);


flag = 0;
if (rpm_check(release:"SLES11", sp:"3", cpu:"x86_64", reference:"xen-kmp-default-4.2.5_21_3.0.101_0.47.99-41.1")) flag++;
if (rpm_check(release:"SLES11", sp:"3", cpu:"x86_64", reference:"xen-libs-4.2.5_21-41.1")) flag++;
if (rpm_check(release:"SLES11", sp:"3", cpu:"x86_64", reference:"xen-tools-domU-4.2.5_21-41.1")) flag++;
if (rpm_check(release:"SLES11", sp:"3", cpu:"x86_64", reference:"xen-4.2.5_21-41.1")) flag++;
if (rpm_check(release:"SLES11", sp:"3", cpu:"x86_64", reference:"xen-doc-html-4.2.5_21-41.1")) flag++;
if (rpm_check(release:"SLES11", sp:"3", cpu:"x86_64", reference:"xen-doc-pdf-4.2.5_21-41.1")) flag++;
if (rpm_check(release:"SLES11", sp:"3", cpu:"x86_64", reference:"xen-libs-32bit-4.2.5_21-41.1")) flag++;
if (rpm_check(release:"SLES11", sp:"3", cpu:"x86_64", reference:"xen-tools-4.2.5_21-41.1")) flag++;
if (rpm_check(release:"SLES11", sp:"3", cpu:"x86_64", reference:"xen-kmp-pae-4.2.5_21_3.0.101_0.47.99-41.1")) flag++;
if (rpm_check(release:"SLES11", sp:"3", cpu:"i586", reference:"xen-kmp-default-4.2.5_21_3.0.101_0.47.99-41.1")) flag++;
if (rpm_check(release:"SLES11", sp:"3", cpu:"i586", reference:"xen-libs-4.2.5_21-41.1")) flag++;
if (rpm_check(release:"SLES11", sp:"3", cpu:"i586", reference:"xen-tools-domU-4.2.5_21-41.1")) flag++;
if (rpm_check(release:"SLES11", sp:"3", cpu:"i586", reference:"xen-kmp-pae-4.2.5_21_3.0.101_0.47.99-41.1")) 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");
}
  • NASL familyDebian Local Security Checks
    NASL idDEBIAN_DLA-964.NASL
    descriptionMultiple vulnerabilities have been discovered in the Xen hypervisor. The Common Vulnerabilities and Exposures project identifies the following problems : CVE-2016-9932 (XSA-200) CMPXCHG8B emulation allows local HVM guest OS users to obtain sensitive information from host stack memory. CVE-2017-7995 Description Xen checks access permissions to MMIO ranges only after accessing them, allowing host PCI device space memory reads. CVE-2017-8903 (XSA-213) Xen mishandles page tables after an IRET hypercall which can lead to arbitrary code execution on the host OS. The vulnerability is only exposed to 64-bit PV guests. CVE-2017-8904 (XSA-214) Xen mishandles the
    last seen2020-03-17
    modified2017-06-02
    plugin id100575
    published2017-06-02
    reporterThis script is Copyright (C) 2017-2020 Tenable Network Security, Inc.
    sourcehttps://www.tenable.com/plugins/nessus/100575
    titleDebian DLA-964-1 : xen security update

References