The do_physdev_op function in Xen 4.1.5, 4.1.6.1, 4.2.2 through 4.2.3, and 4.3.x does not properly restrict access to the (1) PHYSDEVOP_prepare_msix and (2) PHYSDEVOP_release_msix operations, which allows local PV guests to cause a denial of service (host or guest malfunction) or possibly gain privileges via unspecified vectors.

The SUSE Linux Enterprise Server 11 Service Pack 2 LTSS Xen hypervisor and toolset has been updated to fix various security issues and several bugs.

The following security issues have been addressed :

XSA-88: CVE-2014-1950: Use-after-free vulnerability in the xc_cpupool_getinfo function in Xen 4.1.x through 4.3.x, when using a multithreaded toolstack, does not properly handle a failure by the xc_cpumap_alloc function, which allows local users with access to management functions to cause a denial of service (heap corruption) and possibly gain privileges via unspecified vectors. (bnc#861256)

XSA-87: CVE-2014-1666: The do_physdev_op function in Xen 4.1.5, 4.1.6.1, 4.2.2 through 4.2.3, and 4.3.x does not properly restrict access to the (1) PHYSDEVOP_prepare_msix and (2) PHYSDEVOP_release_msix operations, which allows local PV guests to cause a denial of service (host or guest malfunction) or possibly gain privileges via unspecified vectors. (bnc#860302)

XSA-84: CVE-2014-1894: Xen 3.2 (and presumably earlier) exhibit both problems with the overflow issue being present for more than just the suboperations listed above.
(bnc#860163)

XSA-84: CVE-2014-1892 CVE-2014-1893: Xen 3.3 through 4.1, while not affected by the above overflow, have a different overflow issue on FLASK_{GET,SET}BOOL and expose unreasonably large memory allocation to arbitrary guests.
(bnc#860163)

XSA-84: CVE-2014-1891: The FLASK_{GET,SET}BOOL, FLASK_USER and FLASK_CONTEXT_TO_SID suboperations of the flask hypercall are vulnerable to an integer overflow on the input size. The hypercalls attempt to allocate a buffer which is 1 larger than this size and is therefore vulnerable to integer overflow and an attempt to allocate then access a zero byte buffer. (bnc#860163)

XSA-82: CVE-2013-6885: The microcode on AMD 16h 00h through 0Fh processors does not properly handle the interaction between locked instructions and write-combined memory types, which allows local users to cause a denial of service (system hang) via a crafted application, aka the errata 793 issue. (bnc#853049)

XSA-76: CVE-2013-4554: Xen 3.0.3 through 4.1.x (possibly 4.1.6.1), 4.2.x (possibly 4.2.3), and 4.3.x (possibly 4.3.1) does not properly prevent access to hypercalls, which allows local guest users to gain privileges via a crafted application running in ring 1 or 2. (bnc#849668)

XSA-74: CVE-2013-4553: The XEN_DOMCTL_getmemlist hypercall in Xen 3.4.x through 4.3.x (possibly 4.3.1) does not always obtain the page_alloc_lock and mm_rwlock in the same order, which allows local guest administrators to cause a denial of service (host deadlock). (bnc#849667)

XSA-60: CVE-2013-2212: The vmx_set_uc_mode function in Xen 3.3 through 4.3, when disabling chaches, allows local HVM guests with access to memory mapped I/O regions to cause a denial of service (CPU consumption and possibly hypervisor or guest kernel panic) via a crafted GFN range. (bnc#831120)

Also the following non-security bugs have been fixed :

  - Boot Failure with xen kernel in UEFI mode with error 'No     memory for trampoline' (bnc#833483)

  - Fixed Xen hypervisor panic on 8-blades nPar with 46-bit     memory addressing. (bnc#848014)

  - In HP's UEFI x86_64 platform and sles11sp3 with xen     environment, dom0 will soft lockup on multiple blades     nPar. (bnc#842417)

  - Soft lockup with PCI passthrough and many VCPUs     (bnc#846849)

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 running a version of Citrix XenServer that is affected by multiple vulnerabilities :

  - A local privilege escalation vulnerability exists     due to improperly restricted access to     'PHYSDEVOP_{prepare,release}_msix' operations by     unprivileged guests. An attacker with access to a guest     operating system can exploit this issue to gain elevated     privileges on affected computers. (CVE-2014-1666)

  - A local privilege escalation vulnerability exists     due to missing privilege level checks in x86 emulation     of far branches. This flaw exists in the CALL, JMP, and     RETF instructions in the Intel assembly syntax, and the     LCALL, LJMP, and LRET instructions in the AT&T syntax.
    An attacker with access to a guest operating system can     exploit this issue to gain elevated privileges on     affected computers. (CVE-2014-8595)

  - A denial of service vulnerability exists due to a     failure to restrict access to the hypercall argument     translation feature. An attacker with access to a guest     operating system can crash the host with excessive     checks on the final register state for 32-bit guests     running on a 64-bit hypervisor. (CVE-2014-8866)

  - A denial of service vulnerability exists due to     insufficient bounding of 'REP MOVS' to MMIO emulated     inside of the hypervisor. This flaw affects the     'hvm_mmio_intercept()' function in 'intercept.c'. An     attacker with access to a guest operating system can     exploit this issue to crash the host.
    (CVE-2014-8867)

The remote host is affected by the vulnerability described in GLSA-201407-03 (Xen: Multiple Vunlerabilities)

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

    A remote attacker can utilize multiple vectors to execute arbitrary       code, cause Denial of Service, or gain access to data on the host.
  Workaround :

    There is no known workaround at this time.

Xen was updated to fix various bugs and security issues :

Update to Xen version 4.2.4 c/s 26280.

  - bnc#861256 - CVE-2014-1950: xen: XSA-88: use-after-free     in xc_cpupool_getinfo() under memory pressure. (fix     included with update)

  - bnc#863297: xend/pvscsi: recognize also SCSI CDROM     devices

  - bnc#858496 - CVE-2014-1642: Xen: XSA-83: Out-of-memory     condition yielding memory corruption during IRQ setup

  - bnc#860163 - xen: XSA-84: integer overflow in several     XSM/Flask hypercalls (CVE-2014-1891 CVE-2014-1892     CVE-2014-1893 CVE-2014-1894)

  - bnc#860165 - CVE-2014-1895: xen: XSA-85: Off-by-one     error in FLASK_AVC_CACHESTAT hypercall

  - bnc#860300 - CVE-2014-1896: xen: XSA-86: libvchan     failure handling malicious ring indexes

  - bnc#860302 - CVE-2014-1666: xen: XSA-87:
    PHYSDEVOP_(prepare,release)_msix exposed to unprivileged     guests

  - bnc#858311 - Server is not booting in kernel XEN after     latest updates - (XEN) setup 0000:00:18.0 for d0 failed     (-19)

  - bnc#858496 - CVE-2014-1642: Xen: XSA-83: Out-of-memory     condition yielding memory corruption during IRQ setup

  - bnc#853049 - CVE-2013-6885: xen: XSA-82: Guest     triggerable AMD CPU erratum may cause host hang

  - bnc#853048 - CVE-2013-6400: xen: XSA-80: IOMMU TLB     flushing may be inadvertently suppressed

  - bnc#831120 - CVE-2013-2212: xen: XSA-60: Excessive time     to disable caching with HVM guests with PCI passthrough

  - bnc#848014 - [HP HPS] Xen hypervisor panics on 8-blades     nPar with 46-bit memory addressing

  - bnc#833251 - [HP BCS SLES11 Bug]: In HPs UEFI x86_64     platform and with xen environment, in booting stage ,xen     hypervisor will panic.

  - pygrub: Support (/dev/xvda) style disk specifications

  - bnc#849667 - CVE-2014-1895: xen: XSA-74: Lock order     reversal between page_alloc_lock and mm_rwlock

  - bnc#849668 - CVE-2013-4554: xen: XSA-76: Hypercalls     exposed to privilege rings 1 and 2 of HVM guests

  - bnc#842417 - In HPs UEFI x86_64 platform and sles11sp3     with xen environment, dom0 will soft lockup on multiple     blades nPar.

  - bnc#848014 - [HP HPS] Xen hypervisor panics on 8-blades     nPar with 46-bit memory addressing

  - bnc#846849 - Soft lockup with PCI passthrough and many     VCPUs

  - bnc#833483 - Boot Failure with xen kernel in UEFI mode     with error 'No memory for trampoline'

  - bnc#849665 - CVE-2013-4551: xen: XSA-75: Host crash due     to guest VMX instruction execution

  - The upstream version of checking for xend when using the     'xl' command is used is not working.

  - bnc#840997 - It is possible to start a VM twice on the     same node.

  - bnc#848657 - xen: CVE-2013-4494: XSA-73: Lock order     reversal between page allocation and grant table locks

The SUSE Linux Enterprise Server 11 Service Pack 3 Xen hypervisor and toolset has been updated to 4.2.4 to fix various bugs and security issues :

The following security issues have been addressed :

  - XSA-60: CVE-2013-2212: The vmx_set_uc_mode function in     Xen 3.3 through 4.3, when disabling chaches, allows     local HVM guests with access to memory mapped I/O     regions to cause a denial of service (CPU consumption     and possibly hypervisor or guest kernel panic) via a     crafted GFN range. (bnc#831120)

  - XSA-80: CVE-2013-6400: Xen 4.2.x and 4.3.x, when using     Intel VT-d and a PCI device has been assigned, does not     clear the flag that suppresses IOMMU TLB flushes when     unspecified errors occur, which causes the TLB entries     to not be flushed and allows local guest administrators     to cause a denial of service (host crash) or gain     privileges via unspecified vectors. (bnc#853048)

  - XSA-82: CVE-2013-6885: The microcode on AMD 16h 00h     through 0Fh processors does not properly handle the     interaction between locked instructions and     write-combined memory types, which allows local users to     cause a denial of service (system hang) via a crafted     application, aka the errata 793 issue. (bnc#853049)

  - XSA-83: CVE-2014-1642: The IRQ setup in Xen 4.2.x and     4.3.x, when using device passthrough and configured to     support a large number of CPUs, frees certain memory     that may still be intended for use, which allows local     guest administrators to cause a denial of service     (memory corruption and hypervisor crash) and possibly     execute arbitrary code via vectors related to an     out-of-memory error that triggers a (1) use-after-free     or (2) double free. (bnc#860092)

  - XSA-84: CVE-2014-1891: The FLASK_{GET,SET}BOOL,     FLASK_USER and FLASK_CONTEXT_TO_SID suboperations of the     flask hypercall are vulnerable to an integer overflow on     the input size. The hypercalls attempt to allocate a     buffer which is 1 larger than this size and is therefore     vulnerable to integer overflow and an attempt to     allocate then access a zero byte buffer. (bnc#860163)

  - XSA-84: CVE-2014-1892 / CVE-2014-1893: Xen 3.3 through     4.1, while not affected by the above overflow, have a     different overflow issue on FLASK_{GET,SET}BOOL and     expose unreasonably large memory allocation to     aribitrary guests. (bnc#860163)

  - XSA-84: CVE-2014-1894: Xen 3.2 (and presumably earlier)     exhibit both problems with the overflow issue being     present for more than just the suboperations listed     above. (bnc#860163)

  - XSA-85: CVE-2014-1895: The FLASK_AVC_CACHESTAT     hypercall, which provides access to per-cpu statistics     on the Flask security policy, incorrectly validates the     CPU for which statistics are being requested.
    (bnc#860165)

  - XSA-86: CVE-2014-1896: libvchan (a library for     inter-domain communication) does not correctly handle     unusual or malicious contents in the xenstore ring. A     malicious guest can exploit this to cause a     libvchan-using facility to read or write past the end of     the ring. (bnc#860300)

  - XSA-87: CVE-2014-1666: The do_physdev_op function in Xen     4.1.5, 4.1.6.1, 4.2.2 through 4.2.3, and 4.3.x does not     properly restrict access to the (1)     PHYSDEVOP_prepare_msix and (2) PHYSDEVOP_release_msix     operations, which allows local PV guests to cause a     denial of service (host or guest malfunction) or     possibly gain privileges via unspecified vectors.
    (bnc#860302)

  - XSA-88: CVE-2014-1950: Use-after-free vulnerability in     the xc_cpupool_getinfo function in Xen 4.1.x through     4.3.x, when using a multithreaded toolstack, does not     properly handle a failure by the xc_cpumap_alloc     function, which allows local users with access to     management functions to cause a denial of service (heap     corruption) and possibly gain privileges via unspecified     vectors. (bnc#861256)

Also the following non-security bugs have been fixed :

  - Fixed boot problems with Xen kernel. '(XEN) setup     0000:00:18.0 for d0 failed (-19)'. (bnc#858311)

  - Fixed Xen hypervisor panic on 8-blades nPar with 46-bit     memory addressing. (bnc#848014)

  - Fixed Xen hypervisor panic in HP's UEFI x86_64 platform     and with xen environment, in booting stage. (bnc#833251)

  - xend/pvscsi: recognize also SCSI CDROM devices.
    (bnc#863297)

  - pygrub: Support (/dev/xvda) style disk specifications

PHYSDEVOP_{prepare,release}_msix exposed to unprivileged pv guests, Out-of-memory condition yielding memory corruption during IRQ setup

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
83613	SUSE SLES11 Security Update : Xen (SUSE-SU-2014:0372-1)	Nessus	SuSE Local Security Checks	high
79745	Citrix XenServer Multiple Vulnerabilities (CTX200288)	Nessus	Misc.	critical
76544	GLSA-201407-03 : Xen: Multiple Vunlerabilities	Nessus	Gentoo Local Security Checks	high
75312	openSUSE Security Update : xen (openSUSE-SU-2014:0483-1)	Nessus	SuSE Local Security Checks	high
73015	SuSE 11.3 Security Update : Xen (SAT Patch Number 8973)	Nessus	SuSE Local Security Checks	high
72252	Fedora 19 : xen-4.2.3-14.fc19 (2014-1559)	Nessus	Fedora Local Security Checks	high
72251	Fedora 20 : xen-4.3.1-8.fc20 (2014-1552)	Nessus	Fedora Local Security Checks	high

Detections

Analytics

CVE-2014-1666

high

Tenable Plugins

high

critical

high

high

high

high

high