ID CVE-2018-15469
Summary An issue was discovered in Xen through 4.11.x. ARM never properly implemented grant table v2, either in the hypervisor or in Linux. Unfortunately, an ARM guest can still request v2 grant tables; they will simply not be properly set up, resulting in subsequent grant-related hypercalls hitting BUG() checks. An unprivileged guest can cause a BUG() check in the hypervisor, resulting in a denial-of-service (crash).
References
Vulnerable Configurations
  • Xen 4.11.0
    cpe:2.3:o:xen:xen:4.11.0
  • Debian Linux 8.0 (Jessie)
    cpe:2.3:o:debian:debian_linux:8.0
CVSS
Base: 4.9
Impact:
Exploitability:
CWE CWE-400
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 via4
  • NASL family SuSE Local Security Checks
    NASL id OPENSUSE-2018-1624.NASL
    description This update for xen fixes the following issues : Update to Xen 4.10.2 bug fix release (bsc#1027519). Security vulnerabilities fixed : - CVE-2018-19961, CVE-2018-19962: Fixed an issue related to insufficient TLB flushing with AMD IOMMUs, which potentially allowed a guest to escalate its privileges, may cause a Denial of Service (DoS) affecting the entire host, or may be able to access data it is not supposed to access. (XSA-275) (bsc#1115040) - CVE-2018-19965: Fixed an issue related to the INVPCID instruction in case non-canonical addresses are accessed, which may allow a guest to cause Xen to crash, resulting in a Denial of Service (DoS) affecting the entire host. (XSA-279) (bsc#1115045) - CVE-2018-19966: Fixed an issue related to a previous fix for XSA-240, which conflicted with shadow paging and allowed a guest to cause Xen to crash, resulting in a Denial of Service (DoS). (XSA-280) (bsc#1115047) - CVE-2018-18883: Fixed an issue related to inproper restriction of nested VT-x, which allowed a guest to cause Xen to crash, resulting in a Denial of Service (DoS). (XSA-278) (bsc#1114405) - CVE-2018-15468: Fixed incorrect MSR_DEBUGCTL handling, which allowed guests to enable Branch Trace Store and may cause a Denial of Service (DoS) of the entire host. (XSA-269) (bsc#1103276) - CVE-2018-15469: Fixed use of v2 grant tables on ARM, which were not properly implemented and may cause a Denial of Service (DoS). (XSA-268) (bsc#1103275) - CVE-2018-15470: Fixed an issue in the logic in oxenstored for handling writes, which allowed a guest to write memory unbounded leading to system-wide Denial of Service (DoS). (XSA-272) (bsc#1103279) - CVE-2018-3646: Mitigations for VMM aspects of L1 Terminal Fault (XSA-273) (bsc#1091107) Other bugs fixed : - Fixed an issue related to a domU hang on SLE12-SP3 HV (bsc#1108940) - Fixed an issue with xpti=no-dom0 not working as expected (bsc#1105528) - Fixed a kernel oops related to fs/dcache.c called by d_materialise_unique() (bsc#1094508) This update was imported from the SUSE:SLE-15:Update update project.
    last seen 2019-02-21
    modified 2018-12-31
    plugin id 119951
    published 2018-12-31
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=119951
    title openSUSE Security Update : xen (openSUSE-2018-1624) (Foreshadow)
  • NASL family SuSE Local Security Checks
    NASL id SUSE_SU-2018-4300-1.NASL
    description This update for xen fixes the following issues : Update to Xen 4.10.2 bug fix release (bsc#1027519). Security vulnerabilities fixed : CVE-2018-19961, CVE-2018-19962: Fixed an issue related to insufficient TLB flushing with AMD IOMMUs, which potentially allowed a guest to escalate its privileges, may cause a Denial of Service (DoS) affecting the entire host, or may be able to access data it is not supposed to access. (XSA-275) (bsc#1115040) CVE-2018-19965: Fixed an issue related to the INVPCID instruction in case non-canonical addresses are accessed, which may allow a guest to cause Xen to crash, resulting in a Denial of Service (DoS) affecting the entire host. (XSA-279) (bsc#1115045) CVE-2018-19966: Fixed an issue related to a previous fix for XSA-240, which conflicted with shadow paging and allowed a guest to cause Xen to crash, resulting in a Denial of Service (DoS). (XSA-280) (bsc#1115047) CVE-2018-18883: Fixed an issue related to inproper restriction of nested VT-x, which allowed a guest to cause Xen to crash, resulting in a Denial of Service (DoS). (XSA-278) (bsc#1114405) CVE-2018-15468: Fixed incorrect MSR_DEBUGCTL handling, which allowed guests to enable Branch Trace Store and may cause a Denial of Service (DoS) of the entire host. (XSA-269) (bsc#1103276) CVE-2018-15469: Fixed use of v2 grant tables on ARM, which were not properly implemented and may cause a Denial of Service (DoS). (XSA-268) (bsc#1103275) CVE-2018-15470: Fixed an issue in the logic in oxenstored for handling writes, which allowed a guest to write memory unbounded leading to system-wide Denial of Service (DoS). (XSA-272) (bsc#1103279) CVE-2018-3646: Mitigations for VMM aspects of L1 Terminal Fault (XSA-273) (bsc#1091107) Other bugs fixed: Fixed an issue related to a domU hang on SLE12-SP3 HV (bsc#1108940) Fixed an issue with xpti=no-dom0 not working as expected (bsc#1105528) Fixed a kernel oops related to fs/dcache.c called by d_materialise_unique() (bsc#1094508) 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 seen 2019-02-21
    modified 2019-01-02
    plugin id 120196
    published 2019-01-02
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=120196
    title SUSE SLED15 / SLES15 Security Update : xen (SUSE-SU-2018:4300-1) (Foreshadow)
  • NASL family Misc.
    NASL id XEN_SERVER_XSA-268.NASL
    description According to its self-reported version number, the Xen hypervisor installed on the remote host is affected by a denial of service vulnerability. 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 2019-02-21
    modified 2018-12-07
    plugin id 112156
    published 2018-08-28
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=112156
    title Xen Project ARM Grant Table v2 DoS (XSA-268)
  • NASL family SuSE Local Security Checks
    NASL id OPENSUSE-2018-1331.NASL
    description This update for xen fixes the following issues : XEN was updated to the Xen 4.9.3 bug fix only release (bsc#1027519) - CVE-2018-17963: qemu_deliver_packet_iov accepted packet sizes greater than INT_MAX, which allows attackers to cause a denial of service or possibly have unspecified other impact. (bsc#1111014) - CVE-2018-15470: oxenstored might not have enforced the configured quota-maxentity. This allowed a malicious or buggy guest to write as many xenstore entries as it wishes, causing unbounded memory usage in oxenstored. This can lead to a system-wide DoS. (XSA-272) (bsc#1103279) - CVE-2018-15469: ARM never properly implemented grant table v2, either in the hypervisor or in Linux. Unfortunately, an ARM guest can still request v2 grant tables; they will simply not be properly set up, resulting in subsequent grant-related hypercalls hitting BUG() checks. An unprivileged guest can cause a BUG() check in the hypervisor, resulting in a denial-of-service (crash). (XSA-268) (bsc#1103275) Note that SUSE does not ship ARM Xen, so we are not affected. - CVE-2018-15468: The DEBUGCTL MSR contains several debugging features, some of which virtualise cleanly, but some do not. In particular, Branch Trace Store is not virtualised by the processor, and software has to be careful to configure it suitably not to lock up the core. As a result, it must only be available to fully trusted guests. Unfortunately, in the case that vPMU is disabled, all value checking was skipped, allowing the guest to choose any MSR_DEBUGCTL setting it likes. A malicious or buggy guest administrator (on Intel x86 HVM or PVH) can lock up the entire host, causing a Denial of Service. (XSA-269) (bsc#1103276) - CVE-2018-3646: Systems with microprocessors utilizing speculative execution and address translations may have allowed unauthorized disclosure of information residing in the L1 data cache to an attacker with local user access with guest OS privilege via a terminal page fault and a side-channel analysis. (XSA-273) (bsc#1091107) Non security issues fixed : - The affinity reporting via 'xl vcpu-list' was broken (bsc#1106263) - Kernel oops in fs/dcache.c called by d_materialise_unique() (bsc#1094508) This update was imported from the SUSE:SLE-12-SP3:Update update project.
    last seen 2019-02-21
    modified 2018-11-26
    plugin id 118563
    published 2018-10-31
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=118563
    title openSUSE Security Update : xen (openSUSE-2018-1331) (Foreshadow)
  • NASL family SuSE Local Security Checks
    NASL id SUSE_SU-2018-3490-1.NASL
    description This update for xen fixes the following issues : XEN was updated to the Xen 4.9.3 bug fix only release (bsc#1027519) CVE-2018-17963: qemu_deliver_packet_iov accepted packet sizes greater than INT_MAX, which allows attackers to cause a denial of service or possibly have unspecified other impact. (bsc#1111014) CVE-2018-15470: oxenstored might not have enforced the configured quota-maxentity. This allowed a malicious or buggy guest to write as many xenstore entries as it wishes, causing unbounded memory usage in oxenstored. This can lead to a system-wide DoS. (XSA-272) (bsc#1103279) CVE-2018-15469: ARM never properly implemented grant table v2, either in the hypervisor or in Linux. Unfortunately, an ARM guest can still request v2 grant tables; they will simply not be properly set up, resulting in subsequent grant-related hypercalls hitting BUG() checks. An unprivileged guest can cause a BUG() check in the hypervisor, resulting in a denial-of-service (crash). (XSA-268) (bsc#1103275) Note that SUSE does not ship ARM Xen, so we are not affected. CVE-2018-15468: The DEBUGCTL MSR contains several debugging features, some of which virtualise cleanly, but some do not. In particular, Branch Trace Store is not virtualised by the processor, and software has to be careful to configure it suitably not to lock up the core. As a result, it must only be available to fully trusted guests. Unfortunately, in the case that vPMU is disabled, all value checking was skipped, allowing the guest to choose any MSR_DEBUGCTL setting it likes. A malicious or buggy guest administrator (on Intel x86 HVM or PVH) can lock up the entire host, causing a Denial of Service. (XSA-269) (bsc#1103276) CVE-2018-3646: Systems with microprocessors utilizing speculative execution and address translations may have allowed unauthorized disclosure of information residing in the L1 data cache to an attacker with local user access with guest OS privilege via a terminal page fault and a side-channel analysis. (XSA-273) (bsc#1091107) Non security issues fixed: The affinity reporting via 'xl vcpu-list' was broken (bsc#1106263) Kernel oops in fs/dcache.c called by d_materialise_unique() (bsc#1094508) 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 seen 2019-02-21
    modified 2018-12-01
    plugin id 118491
    published 2018-10-29
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=118491
    title SUSE SLED12 / SLES12 Security Update : xen (SUSE-SU-2018:3490-1) (Foreshadow)
  • NASL family Fedora Local Security Checks
    NASL id FEDORA_2018-915602DF63.NASL
    description L1 Terminal Fault speculative side channel patch bundle [XSA-273, CVE-2018-3620, CVE-2018-3646] drop patches also in the bundle, which also includes Use of v2 grant tables may cause crash on ARM [XSA-268] (#1616081) x86: Incorrect MSR_DEBUGCTL handling lets guests enable BTS [XSA-269] (#1616077) oxenstored does not apply quota-maxentity [XSA-272] (#1616080) Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen 2019-02-21
    modified 2018-11-02
    plugin id 112234
    published 2018-09-04
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=112234
    title Fedora 27 : xen (2018-915602df63) (Foreshadow)
  • NASL family Fedora Local Security Checks
    NASL id FEDORA_2018-683DFDE81A.NASL
    description L1 Terminal Fault speculative side channel patch bundle [XSA-273, CVE-2018-3620, CVE-2018-3646] drop patches also in the bundle, which also includes Use of v2 grant tables may cause crash on ARM [XSA-268] (#1616081) x86: Incorrect MSR_DEBUGCTL handling lets guests enable BTS [XSA-269] (#1616077) oxenstored does not apply quota-maxentity [XSA-272] (#1616080) Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen 2019-02-21
    modified 2019-01-03
    plugin id 120490
    published 2019-01-03
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=120490
    title Fedora 28 : xen (2018-683dfde81a) (Foreshadow)
  • NASL family Gentoo Local Security Checks
    NASL id GENTOO_GLSA-201810-06.NASL
    description The remote host is affected by the vulnerability described in GLSA-201810-06 (Xen: Multiple vulnerabilities) Multiple vulnerabilities have been discovered in Xen. Please review the referenced CVE identifiers for details. Impact : A local attacker could cause a Denial of Service condition or disclose sensitive information. Workaround : There is no known workaround at this time.
    last seen 2019-02-21
    modified 2018-10-31
    plugin id 118506
    published 2018-10-31
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=118506
    title GLSA-201810-06 : Xen: Multiple vulnerabilities (Foreshadow) (Meltdown) (Spectre)
  • NASL family Debian Local Security Checks
    NASL id DEBIAN_DLA-1577.NASL
    description Multiple vulnerabilities have been discovered in the Xen hypervisor, which could result in denial of service, informations leaks or privilege escalation. For Debian 8 'Jessie', these problems have been fixed in version 4.4.4lts4-0+deb8u1. 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.
    last seen 2019-02-21
    modified 2018-11-13
    plugin id 118892
    published 2018-11-13
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=118892
    title Debian DLA-1577-1 : xen security update
refmap via4
gentoo GLSA-201810-06
misc http://xenbits.xen.org/xsa/advisory-268.html
mlist [debian-lts-announce] 20181112 [SECURITY] [DLA 1577-1] xen security update
Last major update 17-08-2018 - 14:29
Published 17-08-2018 - 14:29
Last modified 08-03-2019 - 12:05
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