Vulnerabilities > CVE-2017-15596 - Resource Exhaustion vulnerability in XEN
Attack vector
LOCAL Attack complexity
LOW Privileges required
HIGH Confidentiality impact
NONE Integrity impact
NONE Availability impact
HIGH Summary
An issue was discovered in Xen 4.4.x through 4.9.x allowing ARM guest OS users to cause a denial of service (prevent physical CPU usage) because of lock mishandling upon detection of an add-to-physmap error.
Vulnerable Configurations
| Part | Description | Count |
|---|---|---|
| OS | Xen
| 73 |
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- XML Ping of the Death An attacker initiates a resource depletion attack where a large number of small XML messages are delivered at a sufficiently rapid rate to cause a denial of service or crash of the target. Transactions such as repetitive SOAP transactions can deplete resources faster than a simple flooding attack because of the additional resources used by the SOAP protocol and the resources necessary to process SOAP messages. The transactions used are immaterial as long as they cause resource utilization on the target. In other words, this is a normal flooding attack augmented by using messages that will require extra processing on the target.
- XML Entity Expansion An attacker submits an XML document to a target application where the XML document uses nested entity expansion to produce an excessively large output XML. XML allows the definition of macro-like structures that can be used to simplify the creation of complex structures. However, this capability can be abused to create excessive demands on a processor's CPU and memory. A small number of nested expansions can result in an exponential growth in demands on memory.
- Inducing Account Lockout An attacker leverages the security functionality of the system aimed at thwarting potential attacks to launch a denial of service attack against a legitimate system user. Many systems, for instance, implement a password throttling mechanism that locks an account after a certain number of incorrect log in attempts. An attacker can leverage this throttling mechanism to lock a legitimate user out of their own account. The weakness that is being leveraged by an attacker is the very security feature that has been put in place to counteract attacks.
- Violating Implicit Assumptions Regarding XML Content (aka XML Denial of Service (XDoS)) XML Denial of Service (XDoS) can be applied to any technology that utilizes XML data. This is, of course, most distributed systems technology including Java, .Net, databases, and so on. XDoS is most closely associated with web services, SOAP, and Rest, because remote service requesters can post malicious XML payloads to the service provider designed to exhaust the service provider's memory, CPU, and/or disk space. The main weakness in XDoS is that the service provider generally must inspect, parse, and validate the XML messages to determine routing, workflow, security considerations, and so on. It is exactly these inspection, parsing, and validation routines that XDoS targets. There are three primary attack vectors that XDoS can navigate Target CPU through recursion: attacker creates a recursive payload and sends to service provider Target memory through jumbo payloads: service provider uses DOM to parse XML. DOM creates in memory representation of XML document, but when document is very large (for example, north of 1 Gb) service provider host may exhaust memory trying to build memory objects. XML Ping of death: attack service provider with numerous small files that clog the system. All of the above attacks exploit the loosely coupled nature of web services, where the service provider has little to no control over the service requester and any messages the service requester sends.
Nessus
NASL family Misc. NASL id XEN_SERVER_XSA-237.NASL description According to its self-reported version number, the Xen hypervisor installed on the remote host is affected by multiple vulnerabilities related to the setup of PCI MSI interrupts, which may allow an attacker on the guest to cause a denial of service on the host, potentially disclose sensitive information from the host, or potentially gain elevated privileges on the host. Note that Nessus has checked the changeset versions based on the xen.git change log. Nessus did not check guest hardware configurations or if patches were applied manually to the source code before a recompile and reinstall. last seen 2020-06-01 modified 2020-06-02 plugin id 103972 published 2017-10-19 reporter This script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/103972 title Xen Hypervisor PCI MSI Interrupt Setup Multiple Guest-to-Host Privilege Escalation (XSA-237) code # # (C) Tenable Network Security, Inc. # include("compat.inc"); if (description) { script_id(103972); script_version("1.6"); script_cvs_date("Date: 2019/11/12"); script_cve_id( "CVE-2017-15588", "CVE-2017-15589", "CVE-2017-15590", "CVE-2017-15591", "CVE-2017-15592", "CVE-2017-15593", "CVE-2017-15594", "CVE-2017-15595", "CVE-2017-15596" ); script_bugtraq_id(101490, 101496, 101500); script_xref(name:"IAVB", value:"2017-B-0142"); script_name(english:"Xen Hypervisor PCI MSI Interrupt Setup Multiple Guest-to-Host Privilege Escalation (XSA-237)"); script_summary(english:"Checks 'xl info' output for the Xen hypervisor version."); script_set_attribute(attribute:"synopsis", value: "The remote Xen hypervisor installation is missing a security update."); script_set_attribute(attribute:"description", value: "According to its self-reported version number, the Xen hypervisor installed on the remote host is affected by multiple vulnerabilities related to the setup of PCI MSI interrupts, which may allow an attacker on the guest to cause a denial of service on the host, potentially disclose sensitive information from the host, or potentially gain elevated privileges on the host. Note that Nessus has checked the changeset versions based on the xen.git change log. Nessus did not check guest hardware configurations or if patches were applied manually to the source code before a recompile and reinstall."); script_set_attribute(attribute:"see_also", value:"http://xenbits.xen.org/xsa/advisory-237.html"); script_set_attribute(attribute:"see_also", value:"https://xenbits.xen.org/gitweb/?p=xen.git;a=summary"); script_set_attribute(attribute:"solution", value: "Apply the appropriate patch according to the vendor advisory."); 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:POC/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:P/RL:O/RC:C"); script_set_attribute(attribute:"cvss_score_source", value:"CVE-2017-15595"); script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available"); script_set_attribute(attribute:"exploit_available", value:"true"); script_set_attribute(attribute:"vuln_publication_date", value:"2017/10/12"); script_set_attribute(attribute:"patch_publication_date", value:"2017/10/12"); script_set_attribute(attribute:"plugin_publication_date", value:"2017/10/19"); script_set_attribute(attribute:"potential_vulnerability", value:"true"); script_set_attribute(attribute:"plugin_type", value:"local"); script_set_attribute(attribute:"cpe", value:"cpe:/o:xen:xen"); script_set_attribute(attribute:"stig_severity", value:"I"); script_end_attributes(); script_category(ACT_GATHER_INFO); script_family(english:"Misc."); script_copyright(english:"This script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof."); script_dependencies("xen_server_detect.nbin"); script_require_keys("installed_sw/Xen Hypervisor", "Settings/ParanoidReport"); exit(0); } include("audit.inc"); include("global_settings.inc"); include("install_func.inc"); include("misc_func.inc"); app_name = "Xen Hypervisor"; install = get_single_install(app_name:app_name); if (report_paranoia < 2) audit(AUDIT_PARANOID); version = install['version']; display_version = install['display_version']; path = install['path']; managed_status = install['Managed status']; changeset = install['Changeset']; if (!empty_or_null(changeset)) display_version += " (changeset " + changeset + ")"; # Installations that are vendor-managed are handled by OS-specific local package checks if (managed_status == "managed") audit(AUDIT_INST_PATH_NOT_VULN, app_name, display_version, path); # XSA-237 fixes['4.5']['fixed_ver'] = '4.5.5'; fixes['4.5']['fixed_ver_display'] = '4.5.5 (changeset 7afc8ad)'; fixes['4.5']['affected_ver_regex'] = '^4\\.5\\.'; fixes['4.5']['affected_changesets'] = make_list("72c107b", "5659aa5", "a224de6", "6442fa9", "db487a6", "709230f", "83724d9", "04b8c4c", "0b2ceae", "e3f0768", "d5a5231", "c5b0fe5", "136ff4e", "42c8ba5", "d38489d", "df59014", "3217129", "4964e86", "c079597", "6ec173b", "a373456", "0780e81", "e5ef76d", "25eaa86", "ae02360", "5597df9", "c5de05e", "773094e", "e39a248", "7b3712a", "be35327", "8825df1", "d7e3725", "6eb61e4", "b1fcfed", "5779d6a", "afdd77e", "c18367a", "7b7fd80", "b30e165", "62ef9b2", "8071724", "235b5d5", "a28b99d", "ff294fc", "bc01e2d", "da50922", "386cc94", "139960f", "ec3ddd6", "988929a", "1c48dff", "20d4248", "9610422", "cd76cd3", "455fd66", "b820c31", "ac3d8bc", "cde86fc", "1678521", "83cb2db", "43d06ef", "2b17bf4", "1a2bda5", "0bd7faf", "e3426e2", "37281bc", "27be856", "bdf3ef1", "cc325c0", "8e7b84d", "387b8ae", "34fbae7", "1530da2", "274a1f6", "b679cfa", "877b760", "cfe165d", "84e4e56", "e4ae4b0"); fixes['4.6']['fixed_ver'] = '4.6.6'; fixes['4.6']['fixed_ver_display'] = '4.6.6 (changeset 9bac910)'; fixes['4.6']['affected_ver_regex'] = '^4\\.6\\.'; fixes['4.6']['affected_changesets'] = make_list("c7a43e3", "913d4f8", "c5881c5", "b0239cd", "78fd0c3", "9079e0d", "1658a87", "22b6dfa", "a8cd231", "629eddd", "64c03bb", "b4660b4", "1ac8162", "747df3c", "5ae011e", "f974d32", "3300ad3", "d708b69"); fixes['4.7']['fixed_ver'] = '4.7.4'; fixes['4.7']['fixed_ver_display'] = '4.7.4-pre (changeset e3f7a64)'; fixes['4.7']['affected_ver_regex'] = '^4\\.7\\.'; fixes['4.7']['affected_changesets'] = make_list("957ad23", "b1ae705", "3add76f", "314a8fc", "d6aad63", "7c99633", "145c18d", "c3fa5cd", "487f8f9", "ffcfc40", "c7783d9", "3331050", "83966a3", "a67b223", "68dbba2", "2728470", "dea68ed", "9d12253", "73d7bc5", "b704b1a", "ca4ef7b", "ece330a", "3d63ebc", "30d50f8", "2dc3cdb", "5151257", "c9f3ca0", "e873251", "8aebf85", "c362cde", "fece08a"); fixes['4.8']['fixed_ver'] = '4.8.3'; fixes['4.8']['fixed_ver_display'] = '4.8.3-pre (changeset 1960ca8)'; fixes['4.8']['affected_ver_regex'] = '^4\\.8\\.'; fixes['4.8']['affected_changesets'] = make_list("866cfa1", "ddd6e41", "370cc9a", "39e3024", "9f092f5", "667f70e", "2116fec", "1a535c3", "ee3fc24", "d623d82", "dda458c", "c642b12", "80d7ef3", "ff4f60a", "36898eb", "4d7ccae", "e574046", "90dafa4", "c020cf2"); fixes['4.9']['fixed_ver'] = '4.9.1'; fixes['4.9']['fixed_ver_display'] = '4.9.1-pre (changeset 44ceb19)'; fixes['4.9']['affected_ver_regex'] = '^4\\.9\\.'; fixes['4.9']['affected_changesets'] = make_list("ae45442", "784afd9", "22032b2", "58da67f", "d1b64cc", "9cde7a8", "1cdcb36", "84c039e", "b244ac9", "612044a", "e8fd372", "a568e25", "8fef83e", "478e40c", "22ea731", "e7703a2", "91ded3b", "2cc3d32", "79775f5", "43cb0c4", "4821228", "d23bcc5", "308654c", "6fd84b3", "89b36cc", "a9ecd60", "798f6c9", "6508278", "5587d9a", "527fc5c", "5ff1de3", "692ed82", "9bf14bb", "c57b1f9", "6b147fd", "0e186e3", "afc5ebf", "266fc0e", "4698106", "f4f02f1", "0fada05", "ab4eb6c", "b29ecc7", "a11d14b", "107401e", "1b7834a"); fix = NULL; foreach ver_branch (keys(fixes)) { if (version =~ fixes[ver_branch]['affected_ver_regex']) { ret = ver_compare(ver:version, fix:fixes[ver_branch]['fixed_ver']); if (ret < 0) fix = fixes[ver_branch]['fixed_ver_display']; else if (ret == 0) { if (empty_or_null(changeset)) fix = fixes[ver_branch]['fixed_ver_display']; else foreach affected_changeset (fixes[ver_branch]['affected_changesets']) if (changeset == affected_changeset) fix = fixes[ver_branch]['fixed_ver_display']; } } } if (empty_or_null(fix)) audit(AUDIT_INST_PATH_NOT_VULN, app_name, display_version, path); items = make_array("Installed version", display_version, "Fixed version", fix, "Path", path); order = make_list("Path", "Installed version", "Fixed version"); report = report_items_str(report_items:items, ordered_fields:order) + '\n'; security_report_v4(port:0, extra:report, severity:SECURITY_HOLE);NASL family Debian Local Security Checks NASL id DEBIAN_DSA-3969.NASL description Multiple vulnerabilities have been discovered in the Xen hypervisor : - CVE-2017-10912 Jann Horn discovered that incorrectly handling of page transfers might result in privilege escalation. - CVE-2017-10913 / CVE-2017-10914 Jann Horn discovered that race conditions in grant handling might result in information leaks or privilege escalation. - CVE-2017-10915 Andrew Cooper discovered that incorrect reference counting with shadow paging might result in privilege escalation. - CVE-2017-10916 Andrew Cooper discovered an information leak in the handling of the Memory Protection Extensions (MPX) and Protection Key (PKU) CPU features. This only affects Debian stretch. - CVE-2017-10917 Ankur Arora discovered a NULL pointer dereference in event polling, resulting in denial of service. - CVE-2017-10918 Julien Grall discovered that incorrect error handling in physical-to-machine memory mappings may result in privilege escalation, denial of service or an information leak. - CVE-2017-10919 Julien Grall discovered that incorrect handling of virtual interrupt injection on ARM systems may result in denial of service. - CVE-2017-10920 / CVE-2017-10921 / CVE-2017-10922 Jan Beulich discovered multiple places where reference counting on grant table operations was incorrect, resulting in potential privilege escalation. - CVE-2017-12135 Jan Beulich found multiple problems in the handling of transitive grants which could result in denial of service and potentially privilege escalation. - CVE-2017-12136 Ian Jackson discovered that race conditions in the allocator for grant mappings may result in denial of service or privilege escalation. This only affects Debian stretch. - CVE-2017-12137 Andrew Cooper discovered that incorrect validation of grants may result in privilege escalation. - CVE-2017-12855 Jan Beulich discovered that incorrect grant status handling, thus incorrectly informing the guest that the grant is no longer in use. - XSA-235 (no CVE yet) Wei Liu discovered that incorrect locking of add-to-physmap operations on ARM may result in denial of service. last seen 2020-06-01 modified 2020-06-02 plugin id 103146 published 2017-09-13 reporter This script is Copyright (C) 2017-2018 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/103146 title Debian DSA-3969-1 : xen - security update NASL family Misc. NASL id XEN_SERVER_XSA-241.NASL description According to its self-reported version number, the Xen hypervisor installed on the remote host is affected by a race condition that is triggered when handling TLB flush requests. This allows an attacker on the guest to access all system memory, allowing them to cause a denial of service, disclose sensitive information, or gain elevated privileges on the host. Note that Nessus has checked the changeset versions based on the xen.git change log. Nessus did not check guest hardware configurations or if patches were applied manually to the source code before a recompile and reinstall. last seen 2020-06-01 modified 2020-06-02 plugin id 103976 published 2017-10-19 reporter This script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/103976 title Xen Hypervisor TLB Flush Request Handling Race Condition System Memory Access Guest-to-Host Privilege Escalation (XSA-241) NASL family Misc. NASL id XEN_SERVER_XSA-238.NASL description According to its self-reported version number, the Xen hypervisor installed on the remote host is affected by unspecified flaws in arch/x86/hvm/ioreq.c that is triggered when handling DMOPs. This may allow an attacker within a guest to consume excessive resources. Note this can only be exploited by domains controlling HVM guests. Note that Nessus has checked the changeset versions based on the xen.git change log. Nessus did not check guest hardware configurations or if patches were applied manually to the source code before a recompile and reinstall. last seen 2020-06-01 modified 2020-06-02 plugin id 103973 published 2017-10-19 reporter This script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/103973 title Xen Hypervisor Multiple Functions DMOP Handling Guest-to-Host DoS (XSA-238) NASL family Misc. NASL id XEN_SERVER_XSA-243.NASL description According to its self-reported version number, the Xen hypervisor installed on the remote host is affected by an unspecified flaw in mm/shadow/multi.c that is triggered during the handling of self-linear shadow mappings with translated guests. This may allow an attacker on the guest to cause a denial of service or gain elevated privileges on the host. Note that Nessus has checked the changeset versions based on the xen.git change log. Nessus did not check guest hardware configurations or if patches were applied manually to the source code before a recompile and reinstall. last seen 2020-06-01 modified 2020-06-02 plugin id 103978 published 2017-10-19 reporter This script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/103978 title Xen Hypervisor Translated Guest Self-linear Shadow Mapping Handling Guest-to-Host Privilege Escalation (XSA-243) NASL family Misc. NASL id XEN_SERVER_XSA-240.NASL description According to its self-reported version number, the Xen hypervisor installed on the remote host is affected by a stack overflow vulnerability that is triggered when recursion is not properly handled when de-typing linear pagetables. By stacking multiple layers of page tables, an attacker within a guest can cause a stack overflow, resulting in the Xen process to crash. Note that Nessus has checked the changeset versions based on the xen.git change log. Nessus did not check guest hardware configurations or if patches were applied manually to the source code before a recompile and reinstall. last seen 2020-06-01 modified 2020-06-02 plugin id 103975 published 2017-10-19 reporter This script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/103975 title Xen Hypervisor Pagetable De-typing Recursion Handling Guest-to-Host DoS (XSA-240) NASL family Misc. NASL id XEN_SERVER_XSA-239.NASL description According to its self-reported version number, the Xen hypervisor installed on the remote host is affected by an unspecified flaw in the hvmemul_do_io() function in arch/x86/hvm/emulate.c that is triggered as an internal structure may contain data from an uninitialized hypervisor stack slot. This may allow an attacker on the guest to gain access to potentially sensitive information from the host. Note that Nessus has checked the changeset versions based on the xen.git change log. Nessus did not check guest hardware configurations or if patches were applied manually to the source code before a recompile and reinstall. last seen 2020-06-01 modified 2020-06-02 plugin id 103974 published 2017-10-19 reporter This script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/103974 title Xen Hypervisor I/O Intercept Code Hypervisor Stack Guest-to-Host Information Disclosure (XSA-239) NASL family Misc. NASL id XEN_SERVER_XSA-244.NASL description According to its self-reported version number, the Xen hypervisor installed on the remote host is affected by an unspecified flaw that is triggered when, as a new CPU is brought online, it copies certain selector fields from CPU0 last seen 2020-06-01 modified 2020-06-02 plugin id 103979 published 2017-10-19 reporter This script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/103979 title Xen Hypervisor New CPU Interrupt Descriptor Table (IDT) Copy Handling Guest-to-Host Privilege Escalation (XSA-244) NASL family Misc. NASL id XEN_SERVER_XSA-242.NASL description According to its self-reported version number, the Xen hypervisor installed on the remote host is affected by an unspecified flaw in arch/x86/mm.c that is triggered as page type references are not properly handled when performing certain cleanup operations. This allows an attacker on the guest to consume excessive memory, resulting in a denial of service for the host. Note that Nessus has checked the changeset versions based on the xen.git change log. Nessus did not check guest hardware configurations or if patches were applied manually to the source code before a recompile and reinstall. last seen 2020-06-01 modified 2020-06-02 plugin id 103977 published 2017-10-19 reporter This script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/103977 title Xen Hypervisor Page Type Reference Handling Memory Exhaustion Guest-to-Host DoS (XSA-242)