An issue was discovered in Xen 4.9.x through 4.11.x, on Intel x86 platforms, allowing x86 HVM and PVH guests to cause a host OS denial of service (NULL pointer dereference) or possibly have unspecified other impact because nested VT-x is not properly restricted.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - An issue was discovered in Xen 4.9.x through 4.11.x, on Intel x86 platforms, allowing x86 HVM and PVH     guests to cause a host OS denial of service (NULL pointer dereference) or possibly have unspecified other     impact because nested VT-x is not properly restricted. (CVE-2018-18883)

Note that Nessus relies on the presence of the package as reported by the vendor.

There are packages installed that are affected by multiple vulnerabilities referenced in the following CVEs:

  - An issue was discovered in Xen through 4.11.x allowing x86 PV guest OS users to cause a denial of service
    (host OS crash) or possibly gain host OS privileges because of an interpretation conflict for a union data
    structure associated with shadow paging. NOTE: this issue exists because of an incorrect fix for
    CVE-2017-15595. (CVE-2018-19966)

  - Systems with microprocessors utilizing speculative execution and address translations may allow
    unauthorized disclosure of information residing in the L1 data cache to an attacker with local user access
    via a terminal page fault and a side-channel analysis. (CVE-2018-3620)

  - Systems with microprocessors utilizing speculative execution and address translations may allow
    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. (CVE-2018-3646)

There are packages installed that are affected by multiple vulnerabilities referenced in the following CVEs:

  - An issue was discovered in Xen through 4.11.x allowing x86 PV guest OS users to cause a denial of service
    (host OS crash) or possibly gain host OS privileges because of an interpretation conflict for a union data
    structure associated with shadow paging. NOTE: this issue exists because of an incorrect fix for
    CVE-2017-15595. (CVE-2018-19966)

  - An issue was discovered in Xen 4.9.x through 4.11.x, on Intel x86 platforms, allowing x86 HVM and PVH
    guests to cause a host OS denial of service (NULL pointer dereference) or possibly have unspecified other
    impact because nested VT-x is not properly restricted. (CVE-2018-18883)

  - An issue was discovered in Xen through 4.11.x on AMD x86 platforms, possibly allowing guest OS users to
    gain host OS privileges because TLB flushes do not always occur after IOMMU mapping changes.
    (CVE-2018-19961)

  - An issue was discovered in Xen through 4.11.x on AMD x86 platforms, possibly allowing guest OS users to
    gain host OS privileges because small IOMMU mappings are unsafely combined into larger ones.
    (CVE-2018-19962)

  - An issue was discovered in Xen through 4.11.x allowing 64-bit PV guest OS users to cause a denial of
    service (host OS crash) because #GP[0] can occur after a non-canonical address is passed to the TLB
    flushing code. NOTE: this issue exists because of an incorrect CVE-2017-5754 (aka Meltdown) mitigation.
    (CVE-2018-19965)

There are packages installed that are affected by multiple vulnerabilities referenced in the following CVEs:

  - An issue was discovered in Xen through 4.11.x allowing x86 PV guest OS users to cause a denial of service
    (host OS crash) or possibly gain host OS privileges because of an interpretation conflict for a union data
    structure associated with shadow paging. NOTE: this issue exists because of an incorrect fix for
    CVE-2017-15595. (CVE-2018-19966)

  - Systems with microprocessors utilizing speculative execution and address translations may allow
    unauthorized disclosure of information residing in the L1 data cache to an attacker with local user access
    via a terminal page fault and a side-channel analysis. (CVE-2018-3620)

  - Systems with microprocessors utilizing speculative execution and address translations may allow
    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. (CVE-2018-3646)

  - An issue was discovered in Xen through 4.11.x. 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. (CVE-2018-15468)

  - 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).
    (CVE-2018-15469)

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.

This update for xen fixes the following issues :

Update to Xen 4.11.1 bug fix release (bsc#1027519)

CVE-2018-17963: Fixed an integer overflow issue in the QEMU emulator, which could occur when a packet with large packet size is processed. A user inside a guest could have used this flaw to crash the qemu process resulting in a Denial of Service (DoS). (bsc#1111014)

CVE-2018-18849: Fixed an out of bounds memory access in the LSI53C895A SCSI host bus adapter emulation, which allowed a user and/or process to crash the qemu process resulting in a Denial of Service (DoS).
(bsc#1114423)

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-2018-19961, 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-2018-19963: Fixed the allocation of pages used to communicate with external emulators, which may have cuased Xen to crash, resulting in a Denial of Service (DoS). (XSA-276) (bsc#1115043)

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-2018-19967: Fixed HLE constructs that allowed guests to lock up the host, resulting in a Denial of Service (DoS). (XSA-282) (bsc#1114988)

CVE-2018-19964: Fixed the incorrect error handling of p2m page removals, which allowed a guest to cause a deadlock, resulting in a Denial of Service (DoS) affecting the entire host. (XSA-277) (bsc#1115044)

CVE-2018-19665: Fixed an integer overflow resulting in memory corruption in various Bluetooth functions, allowing this to crash qemu process resulting in Denial of Service (DoS). (bsc#1117756).

Other bugs fixed: Fixed an issue related to a domU hang on SLE12-SP3 HV (bsc#1108940)

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.

x86: Nested VT-x usable even when disabled [XSA-278]

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.

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.

This update for xen fixes the following issues :

Security issues fixed :

CVE-2018-18849: Fixed an out of bounds memory access issue was found in the LSI53C895A SCSI Host Bus Adapter emulation while writing a message in lsi_do_msgin (bsc#1114423).

CVE-2018-18883: Fixed a NULL pointer dereference that could have been triggered by nested VT-x that where not properly restricted (XSA-278)(bsc#1114405).

CVE-2018-19965: Fixed denial of service issue from attempting to use INVPCID with a non-canonical addresses (XSA-279)(bsc#1115045).

CVE-2018-19966: Fixed issue introduced by XSA-240 that could have caused conflicts with shadow paging (XSA-280)(bsc#1115047).

CVE-2018-19961 CVE-2018-19962: Fixed insufficient TLB flushing / improper large page mappings with AMD IOMMUs (XSA-275)(bsc#1115040).

Non-security issues fixed: Added upstream bug fixes (bsc#1027519).

Fixed XEN SLE12-SP1 domU hang on SLE12-SP3 HV (bsc#1108940).

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.

This update for xen fixes the following issues :

Security issues fixed :

  - CVE-2018-18849: Fixed an out of bounds memory access     issue was found in the LSI53C895A SCSI Host Bus Adapter     emulation while writing a message in lsi_do_msgin     (bsc#1114423).

  - CVE-2018-18883: Fixed a NULL pointer dereference that     could have been triggered by nested VT-x that where not     properly restricted (XSA-278)(bsc#1114405).

  - CVE-2018-19965: Fixed denial of service issue from     attempting to use INVPCID with a non-canonical addresses     (XSA-279)(bsc#1115045).

  - CVE-2018-19966: Fixed issue introduced by XSA-240 that     could have caused conflicts with shadow paging     (XSA-280)(bsc#1115047).

  - CVE-2018-19961 CVE-2018-19962: Fixed insufficient TLB     flushing / improper large page mappings with AMD IOMMUs     (XSA-275)(bsc#1115040).

Non-security issues fixed :

  - Added upstream bug fixes (bsc#1027519).

This update was imported from the SUSE:SLE-12-SP3:Update update project.

The version of Citrix XenServer running on the remote host is missing a security hotfix. It is, therefore, affected by by a guest-to-host denial of service vulnerability.

According to its self-reported version number, the Xen hypervisor installed on the remote host is affected by a guest-to-host 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.

ID	Name	Product	Family	Severity
256745	Linux Distros Unpatched Vulnerability : CVE-2018-18883	Nessus	Misc.	high
424700	Alpine: multiple xen packages: security update to 4.11.1-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	high
424700	Alpine: multiple xen packages: security update to 4.11.1-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	high
407911	Alpine: xen: security update to 4.9.3-r1	Tenable Cloud Security	Alpine Linux Local Security Checks	high
407911	Alpine: xen: security update to 4.9.3-r1	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	high
407899	Alpine: xen: security update to 4.8.5-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	high
407899	Alpine: xen: security update to 4.8.5-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	high
407739	Alpine: xen: security update to 4.10.2-r1	Tenable Cloud Security	Alpine Linux Local Security Checks	high
407739	Alpine: xen: security update to 4.10.2-r1	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	high
123167	openSUSE Security Update : xen (openSUSE-2019-1046) (Foreshadow)	Nessus	SuSE Local Security Checks	high
120983	SUSE SLED12 / SLES12 Security Update : xen (SUSE-SU-2019:0003-1)	Nessus	SuSE Local Security Checks	critical
120665	Fedora 29 : xen (2018-a24754252a)	Nessus	Fedora Local Security Checks	high
120529	Fedora 28 : xen (2018-73dd8de892)	Nessus	Fedora Local Security Checks	high
120196	SUSE SLED15 / SLES15 Security Update : xen (SUSE-SU-2018:4300-1) (Foreshadow)	Nessus	SuSE Local Security Checks	high
119951	openSUSE Security Update : xen (openSUSE-2018-1624) (Foreshadow)	Nessus	SuSE Local Security Checks	high
119648	SUSE SLED12 / SLES12 Security Update : xen (SUSE-SU-2018:4070-1)	Nessus	SuSE Local Security Checks	high
119642	openSUSE Security Update : xen (openSUSE-2018-1530)	Nessus	SuSE Local Security Checks	high
118898	Fedora 27 : xen (2018-f20a0cead5)	Nessus	Fedora Local Security Checks	high
118856	Citrix XenServer Nested VT-x Instruction Guest-to-Host DoS (CTX239100)	Nessus	Misc.	high
118570	Xen Project Nested VT-x Instruction Guest-to-Host DoS (XSA-278)	Nessus	Misc.	high

Detections

Analytics

CVE-2018-18883

high

Tenable Plugins

high

high

high

high

high

high

high

high

high

high

critical

high

high

high

high

high

high

high

high

high