Certain MMU virtualization operations in Xen 4.2.x through 4.4.x, when using shadow pagetables, are not preemptible, which allows local HVM guest to cause a denial of service (vcpu consumption) by invoking these operations, which process every page assigned to a guest, a different vulnerability than CVE-2014-5146.

The Virtualization service XEN was updated to fix various bugs and security issues.

The following security issues have been fixed :

XSA-125: Long latency MMIO mapping operations were not preemptible.

CVE-2015-2151: XSA-123: Instructions with register operands ignored eventual segment overrides encoded for them. Due to an insufficiently conditional assignment such a bogus segment override could have, however, corrupted a pointer used subsequently to store the result of the instruction.

CVE-2015-2045: XSA-122: The code handling certain sub-operations of the HYPERVISOR_xen_version hypercall failed to fully initialize all fields of structures subsequently copied back to guest memory. Due to this hypervisor stack contents were copied into the destination of the operation, thus becoming visible to the guest.

CVE-2015-2044: XSA-121: Emulation routines in the hypervisor dealing with certain system devices checked whether the access size by the guest is a supported one. When the access size is unsupported these routines failed to set the data to be returned to the guest for read accesses, so that hypervisor stack contents were copied into the destination of the operation, thus becoming visible to the guest.

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.

The remote host is affected by the vulnerability described in GLSA-201504-04 (Xen: Multiple vulnerabilities)

    Multiple vulnerabilities have been discovered in Xen.  Please review the       CVE identifiers referenced below for details.
  Impact :

    A local attacker could possibly cause a Denial of Service condition or       obtain sensitive information.
  Workaround :

    There is no known workaround at this time.

The XEN virtualization was updated to fix bugs and security issues :

Security issues fixed: CVE-2015-0361: XSA-116: xen: xen crash due to use after free on hvm guest teardown 

CVE-2014-9065, CVE-2014-9066: XSA-114: xen: p2m lock starvation

CVE-2014-9030: XSA-113: Guest effectable page reference leak in MMU_MACHPHYS_UPDATE handling

CVE-2014-8867: XSA-112: xen: Insufficient bounding of 'REP MOVS' to MMIO emulated inside the hypervisor

CVE-2014-8866: XSA-111: xen: Excessive checking in compatibility mode hypercall argument translation

CVE-2014-8595: XSA-110: xen: Missing privilege level checks in x86 emulation of far branches

CVE-2014-8594: XSA-109: xen: Insufficient restrictions on certain MMU update hypercalls

CVE-2013-3495: XSA-59: xen: Intel VT-d Interrupt Remapping engines can be evaded by native NMI interrupts

CVE-2014-5146, CVE-2014-5149: xen: XSA-97 Long latency virtual-mmu operations are not preemptible

Bugs fixed :

  - Restore missing fixes from block-dmmd script

  - bnc#904255 - XEN boot hangs in early boot on UEFI system

  - Fix missing banner by restoring figlet program

  - bnc#903357 - Corrupted save/restore test leaves orphaned     data in xenstore

  - bnc#903359 - Temporary migration name is not cleaned up     after migration

  - bnc#903850 - Xen: guest user mode triggerable VM exits     not handled by hypervisor

  - bnc#866902 - Xen save/restore of HVM guests cuts off     disk and networking 

  - bnc#901317 - increase limit domUloader to 32MB

  - bnc#898772 - SLES 12 RC3 - XEN Host crashes when     assigning non-VF device (SR-IOV) to guest

  - bnc#882089 - Windows 2012 R2 fails to boot up with     greater than 60 vcpus

  - bsc#900292 - xl: change default dump directory

  - Update xen2libvirt.py to better detect and handle file     formats

  - bnc#882089 - Windows 2012 R2 fails to boot up with     greater than 60 vcpus

  - bnc#897906 - libxc: check return values on mmap() and     madvise() on xc_alloc_hypercall_buffer()

  - bnc#896023 - Adjust xentop column layout

The virtualization software XEN was updated to version 4.3.3 and also to fix bugs and security issues.

Security issues fixed: CVE-2015-0361: XSA-116: xen: xen crash due to use after free on hvm guest teardown 

CVE-2014-9065, CVE-2014-9066: XSA-114: xen: p2m lock starvation

CVE-2014-9030: XSA-113: Guest effectable page reference leak in MMU_MACHPHYS_UPDATE handling

CVE-2014-8867: XSA-112: xen: Insufficient bounding of 'REP MOVS' to MMIO emulated inside the hypervisor

CVE-2014-8866: XSA-111: xen: Excessive checking in compatibility mode hypercall argument translation

CVE-2014-8595: XSA-110: xen: Missing privilege level checks in x86 emulation of far branches

CVE-2014-8594: XSA-109: xen: Insufficient restrictions on certain MMU update hypercalls

CVE-2013-3495: XSA-59: xen: Intel VT-d Interrupt Remapping engines can be evaded by native NMI interrupts

CVE-2014-5146, CVE-2014-5149: xen: XSA-97 Long latency virtual-mmu operations are not preemptible

Bugs fixed :

  - bnc#903357 - Corrupted save/restore test leaves orphaned     data in xenstore

  - bnc#903359 - Temporary migration name is not cleaned up     after migration

  - bnc#903850 - VUL-0: Xen: guest user mode triggerable VM     exits not handled by hypervisor

  - bnc#866902 - L3: Xen save/restore of HVM guests cuts off     disk and networking

  - bnc#901317 - L3: increase limit domUloader to 32MB     domUloader.py

  - bnc#882089 - Windows 2012 R2 fails to boot up with     greater than 60 vcpus

  - bsc#900292 - xl: change default dump directory

  - Update to Xen 4.3.3

The remote OracleVM system is missing necessary patches to address critical security updates : please see Oracle VM Security Advisory OVMSA-2015-0004 for details.

Long latency virtual-mmu operations are not preemptible [XSA-97, CVE-2014-5146]

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

ID	Name	Product	Family	Severity
83717	SUSE SLES10 Security Update : Xen (SUSE-SU-2015:0744-1)	Nessus	SuSE Local Security Checks	high
82734	GLSA-201504-04 : Xen: Multiple vulnerabilities	Nessus	Gentoo Local Security Checks	high
81305	openSUSE Security Update : xen (openSUSE-2015-129)	Nessus	SuSE Local Security Checks	high
81239	openSUSE Security Update : xen (openSUSE-2015-113)	Nessus	SuSE Local Security Checks	high
80928	OracleVM 3.3 : xen (OVMSA-2015-0004)	Nessus	OracleVM Local Security Checks	medium
77361	Fedora 19 : xen-4.2.4-7.fc19 (2014-9493)	Nessus	Fedora Local Security Checks	medium
77360	Fedora 20 : xen-4.3.2-7.fc20 (2014-9472)	Nessus	Fedora Local Security Checks	medium

Detections

Analytics

CVE-2014-5149

medium

Tenable Plugins

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medium

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