OracleVM 3.3 : xen (OVMSA-2016-0103)

Medium Nessus Plugin ID 93396


The remote OracleVM host is missing one or more security updates.


The remote OracleVM system is missing necessary patches to address critical security updates :

- From: Andrew Cooper Subject: x86/shadow: Avoid overflowing sh_ctxt->seg_reg[] hvm_get_seg_reg does not perform a range check on its input segment, calls hvm_get_segment_register and writes straight into sh_ctxt->seg_reg[]. x86_seg_none is outside the bounds of sh_ctxt->seg_reg[], and will hit a BUG in [vmx,svm]_get_segment_register. HVM guests running with shadow paging can end up performing a virtual to linear translation with x86_seg_none. This is used for addresses which are already linear. However, none of this is a legitimate pagetable update, so fail the emulation in such a case. This is XSA-187 (CVE-2016-7094)

- x86/32on64: don't allow recursive page tables from L3 L3 entries are special in PAE mode, and hence can't reasonably be used for setting up recursive (and hence linear) page table mappings. Since abuse is possible when the guest in fact gets run on 4-level page tables, this needs to be excluded explicitly. This is XSA-185.


Update the affected xen / xen-tools packages.

See Also

Plugin Details

Severity: Medium

ID: 93396

File Name: oraclevm_OVMSA-2016-0103.nasl

Version: $Revision: 2.12 $

Type: local

Published: 2016/09/09

Modified: 2017/02/17

Dependencies: 12634

Risk Information

Risk Factor: Medium


Base Score: 6.8

Temporal Score: 5

Vector: CVSS2#AV:L/AC:L/Au:S/C:C/I:C/A:C

Temporal Vector: CVSS2#E:U/RL:OF/RC:C


Base Score: 8.2

Vector: CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Vulnerability Information

CPE: p-cpe:/a:oracle:vm:xen, p-cpe:/a:oracle:vm:xen-tools, cpe:/o:oracle:vm_server:3.3

Required KB Items: Host/local_checks_enabled, Host/OracleVM/release, Host/OracleVM/rpm-list

Exploit Available: false

Exploit Ease: No known exploits are available

Patch Publication Date: 2016/09/08

Reference Information

CVE: CVE-2016-7092, CVE-2016-7094

OSVDB: 143907, 143909

IAVB: 2016-B-0140