x86 PV guests may be able to mask interrupts

ISSUE DESCRIPTION Certain PV guest kernel operations page table writes in particular need emulation, and use Xen's general x86 instruction emulator. This allows a malicious guest kernel which asynchronously modifies its instruction stream to effect the clearing of EFLAGS.IF from the state used to...

Fedora 25 : xen (2016-1b868c23a9)

x86 CMPXCHG8B emulation fails to ignore operand size override XSA-200, CVE-2016-9932 1404262 ---- ARM guests may induce host asynchronous abort XSA-201, CVE-2016-9815, Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website...

Fedora 23 : xen (2016-cc2916dcf4)

ARM guests may induce host asynchronous abort XSA-201, CVE-2016-9815, CVE-2016-9816, CVE-2016-9817, CVE-2016-9818 1399747 qemu: Divide by zero vulnerability in cirrusdocopy 1399055 CVE-2016-9921, CVE-2016-9922 Qemu: 9pfs: memory leakage via proxy/handle callbacks 1402278 qemu ioport array overflo...

x86: Mishandling of SYSCALL singlestep during emulation

ISSUE DESCRIPTION The typical behaviour of singlestepping exceptions is determined at the start of the instruction, with a DB trap being raised at the end of the instruction. SYSCALL and SYSRET, although we don't implement it behave differently because the typical behaviour allows userspace to...

CVE-2015-8542: Undefined Security Weakness

An issue was discovered in Open-Xchange Guard before 2.2.0-rev8. The "getprivkeybyid" API call is used to download a PGP Private Key for a specific user after providing authentication credentials. Clients provide the "id" and "cid" parameter to specify the current user by its user- and context-ID...

ALPINE-CVE-2016-9101

Memory leak in hw/net/eepro100.c in QEMU aka Quick Emulator allows local guest OS administrators to cause a denial of service memory consumption and QEMU process crash by repeatedly unplugging an i8255x PRO100 NIC device...

Debian DSA-3729-1 : xen - security update

Multiple vulnerabilities have been discovered in the Xen hypervisor. The Common Vulnerabilities and Exposures project identifies the following problems : - CVE-2016-7777 XSA-190 Jan Beulich from SUSE discovered that Xen does not properly honor CR0.TS and CR0.EM for x86 HVM guests, potentially...

qemu ioport array overflow

ISSUE DESCRIPTION The code in qemu which implements ioport read/write looks up the specified ioport address in a dispatch table. The argument to the dispatch function is a uint32t, and is used without a range check, even though the table has entries for only 2^16 ioports. When qemu is used as a...

FreeBSD : xen-kernel -- x86: Disallow L3 recursive pagetable for 32-bit PV guests (45ca25b5-ba4d-11e6-ae1b-002590263bf5)

The Xen Project reports : On real hardware, a 32-bit PAE guest must leave the USER and RW bit clear in L3 pagetable entries, but the pagetable walk behaves as if they were set. The L3 entries are cached in processor registers, and don't actually form part of the pagewalk. When running a 32-bit PV...

FreeBSD : xen-kernel -- CR0.TS and CR0.EM not always honored for x86 HVM guests (4d7cf654-ba4d-11e6-ae1b-002590263bf5)

The Xen Project reports : Instructions touching FPU, MMX, or XMM registers are required to raise a Device Not Available Exception NM when either CR0.EM or CR0.TS are set. Their AVX or AVX-512 extensions would consider only CR0.TS. While during normal operation this is ensured by the hardware, if ...

x86 segment base write emulation lacking canonical address checks

ISSUE DESCRIPTION Both writes to the FS and GS register base MSRs as well as the WRFSBASE and WRGSBASE instructions require their input values to be canonical, or a GP fault will be raised. When the use of those instructions by the hypervisor was enabled, the previous guard against GP faults havi...

x86 task switch to VM86 mode mis-handled

ISSUE DESCRIPTION LDTR, just like TR, is purely a protected mode facility. Hence even when switching to a VM86 mode task, LDTR loading needs to follow protected mode semantics. This was violated by the code. IMPACT On SVM AMD hardware: a malicious unprivileged guest process can escalate its...

x86 null segments not always treated as unusable

ISSUE DESCRIPTION The Xen x86 emulator erroneously failed to consider the unusability of segments when performing memory accesses. The intended behaviour is as follows: The user data segment %ds, %es, %fs and %gs selectors may be NULL in 32-bit to prevent access. In 64-bit, NULL has a special...

Fedora 25 : xen (2016-1d8429b89f)

fix build problem with glibc 2.24 x86: Disallow L3 recursive pagetable for 32-bit PV guests XSA-185, CVE-2016-7092 x86: Mishandling of instruction pointer truncation during emulation XSA-186, CVE-2016-7093 x86 HVM: Overflow of shctxt-segreg XSA-187, CVE-2016-7094 pandoc documentation has dependen...

ALPINE-CVE-2016-8577

Memory leak in the v9fsread function in hw/9pfs/9p.c in QEMU aka Quick Emulator allows local guest OS administrators to cause a denial of service memory consumption via vectors related to an I/O read operation...

UBUNTU-CVE-2016-8910

The rtl8139cplustransmit function in hw/net/rtl8139.c in QEMU aka Quick Emulator allows local guest OS administrators to cause a denial of service infinite loop and CPU consumption by leveraging failure to limit the ring descriptor count...

UBUNTU-CVE-2016-8909

The intelhdaxfer function in hw/audio/intel-hda.c in QEMU aka Quick Emulator allows local guest OS administrators to cause a denial of service infinite loop and CPU consumption via an entry with the same value for buffer length and pointer position...

UBUNTU-CVE-2016-8576

The xhciringfetch function in hw/usb/hcd-xhci.c in QEMU aka Quick Emulator allows local guest OS administrators to cause a denial of service infinite loop and QEMU process crash by leveraging failure to limit the number of link Transfer Request Blocks TRB to process...

openSUSE Security Update : virtualbox (openSUSE-2016-1226)

This update for virtualbox fixes the following issues : - Address CVE-2016-5501, CVE-2016-5538, CVE-2016-5605, CVE-2016-5608, CVE-2016-5610, CVE-2016-5611, CVE-2016-5613 boo1005621. - Reduce memory needs during build. - Version bump to 5.0.28 released 2016-10-18 by Oracle This is a maintenance...

CVE-2016-7777 - Citrix XenServer Security Update

Description of Problem A security vulnerability has been identified in Citrix XenServer that may allow malicious user code within an HVM guest VM to read or modify the contents of certain registers belonging to other tasks within that same guest VM. This vulnerability affects all currently...