QEMU 0.9.0 does not properly handle changes to removable media, which allows guest OS users to read arbitrary files on the host OS by using the diskformat: parameter in the -usbdevice option to modify the disk-image header to identify a different format, a related issue to CVE-2008-2004.

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

  - CVE-2008-1945: add image format options for USB storage     and removable media

  - CVE-2008-1952: included in fix for CVE-2008-1943     (3.1.4-0.1.3.el5)

The remote Oracle Linux 5 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2008-0892 advisory.

    - Correctly limit PVFB size CVE-2008-1952 (rhbz #447760)

Tenable has extracted the preceding description block directly from the Oracle Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

It was discovered that the hypervisor's para-virtualized framebuffer (PVFB) backend failed to validate the frontend's framebuffer description properly. This could allow a privileged user in the unprivileged domain (DomU) to cause a denial of service, or, possibly, elevate privileges to the privileged domain (Dom0). (CVE-2008-1952)

A flaw was found in the QEMU block format auto-detection, when running fully-virtualized guests and using Qemu images written on removable media (USB storage, 3.5' disks). Privileged users of such fully-virtualized guests (DomU), with a raw-formatted disk image, were able to write a header to that disk image describing another format.
This could allow such guests to read arbitrary files in their hypervisor's host (Dom0). (CVE-2008-1945)

Additionally, the following bug is addressed in this update :

  - The qcow-create command terminated when invoked due to     glibc bounds checking on the realpath() function.

Updated xen packages that resolve a couple of security issues and fix a bug are now available for Red Hat Enterprise Linux 5.

This update has been rated as having important security impact by the Red Hat Security Response Team.

The xen packages contain tools for managing the virtual machine monitor in Red Hat Virtualization.

It was discovered that the hypervisor's para-virtualized framebuffer (PVFB) backend failed to validate the frontend's framebuffer description properly. This could allow a privileged user in the unprivileged domain (DomU) to cause a denial of service, or, possibly, elevate privileges to the privileged domain (Dom0). (CVE-2008-1952)

A flaw was found in the QEMU block format auto-detection, when running fully-virtualized guests and using Qemu images written on removable media (USB storage, 3.5' disks). Privileged users of such fully-virtualized guests (DomU), with a raw-formatted disk image, were able to write a header to that disk image describing another format.
This could allow such guests to read arbitrary files in their hypervisor's host (Dom0). (CVE-2008-1945)

Additionally, the following bug is addressed in this update :

* The qcow-create command terminated when invoked due to glibc bounds checking on the realpath() function.

Users of xen are advised to upgrade to these updated packages, which resolve these security issues and fix this bug.

qemu update to version 0.10.1 fixes the following security issues :

CVE-2008-0928: problems with range checks of block devices CVE-2008-1945: problems with removable media handling CVE-2008-2382:
vnc server DoS CVE-2008-4539: fix a heap overflow in the cirrus VGA implementation CVE-2008-5714: off by one error in vnc password handling

USN-776-1 fixed vulnerabilities in KVM. Due to an incorrect fix, a regression was introduced in Ubuntu 8.04 LTS that caused KVM to fail to boot virtual machines started via libvirt. This update fixes the problem. We apologize for the inconvenience.

Avi Kivity discovered that KVM did not correctly handle certain disk formats. A local attacker could attach a malicious partition that would allow the guest VM to read files on the VM host. (CVE-2008-1945, CVE-2008-2004)

Alfredo Ortega discovered that KVM's VNC protocol handler did not correctly validate certain messages. A remote attacker could send specially crafted VNC messages that would cause KVM to consume CPU resources, leading to a denial of service. (CVE-2008-2382)

Jan Niehusmann discovered that KVM's Cirrus VGA implementation over VNC did not correctly handle certain bitblt operations. A local attacker could exploit this flaw to potentially execute arbitrary code on the VM host or crash KVM, leading to a denial of service. (CVE-2008-4539)

It was discovered that KVM's VNC password checks did not use the correct length. A remote attacker could exploit this flaw to cause KVM to crash, leading to a denial of service.
(CVE-2008-5714).

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

Avi Kivity discovered that KVM did not correctly handle certain disk formats. A local attacker could attach a malicious partition that would allow the guest VM to read files on the VM host. (CVE-2008-1945, CVE-2008-2004)

Alfredo Ortega discovered that KVM's VNC protocol handler did not correctly validate certain messages. A remote attacker could send specially crafted VNC messages that would cause KVM to consume CPU resources, leading to a denial of service. (CVE-2008-2382)

Jan Niehusmann discovered that KVM's Cirrus VGA implementation over VNC did not correctly handle certain bitblt operations. A local attacker could exploit this flaw to potentially execute arbitrary code on the VM host or crash KVM, leading to a denial of service.
(CVE-2008-4539)

It was discovered that KVM's VNC password checks did not use the correct length. A remote attacker could exploit this flaw to cause KVM to crash, leading to a denial of service. (CVE-2008-5714).

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

Several vulnerabilities have been discovered in the QEMU processor emulator. The Common Vulnerabilities and Exposures project identifies the following problems :

  - CVE-2008-0928     Ian Jackson discovered that range checks of file     operations on emulated disk devices were insufficiently     enforced.

  - CVE-2008-1945     It was discovered that an error in the format auto     detection of removable media could lead to the     disclosure of files in the host system.

  - CVE-2008-4539     A buffer overflow has been found in the emulation of the     Cirrus graphics adaptor.

Multiple vulnerabilities have been found in Qemu.

Multiple heap-based buffer overflows in the cirrus_invalidate_region function in the Cirrus VGA extension in QEMU 0.8.2, as used in Xen and possibly other products, might allow local users to execute arbitrary code via unspecified vectors related to attempting to mark non-existent regions as dirty, aka the bitblt heap overflow.
(CVE-2007-1320)

Integer signedness error in the NE2000 emulator in QEMU 0.8.2, as used in Xen and possibly other products, allows local users to trigger a heap-based buffer overflow via certain register values that bypass sanity checks, aka QEMU NE2000 receive integer signedness error.
(CVE-2007-1321)

QEMU 0.8.2 allows local users to halt a virtual machine by executing the icebp instruction. (CVE-2007-1322)

QEMU 0.8.2 allows local users to crash a virtual machine via the divisor operand to the aam instruction, as demonstrated by aam 0x0, which triggers a divide-by-zero error. (CVE-2007-1366)

The NE2000 emulator in QEMU 0.8.2 allows local users to execute arbitrary code by writing Ethernet frames with a size larger than the MTU to the EN0_TCNT register, which triggers a heap-based buffer overflow in the slirp library, aka NE2000 mtu heap overflow.
(CVE-2007-5729)

Heap-based buffer overflow in QEMU 0.8.2, as used in Xen and possibly other products, allows local users to execute arbitrary code via crafted data in the net socket listen option, aka QEMU net socket heap overflow. (CVE-2007-5730)

QEMU 0.9.0 allows local users of a Windows XP SP2 guest operating system to overwrite the TranslationBlock (code_gen_buffer) buffer, and probably have unspecified other impacts related to an overflow, via certain Windows executable programs, as demonstrated by qemu-dos.com.
(CVE-2007-6227)

Qemu 0.9.1 and earlier does not perform range checks for block device read or write requests, which allows guest host users with root privileges to access arbitrary memory and escape the virtual machine.
(CVE-2008-0928)

Changing removable media in QEMU could trigger a bug similar to CVE-2008-2004, which would allow local guest users to read arbitrary files on the host by modifying the header of the image to identify a different format. (CVE-2008-1945) See the diskformat: parameter to the
-usbdevice option.

The drive_init function in QEMU 0.9.1 determines the format of a raw disk image based on the header, which allows local guest users to read arbitrary files on the host by modifying the header to identify a different format, which is used when the guest is restarted.
(CVE-2008-2004) See the -format option.

The updated packages have been patched to fix these issues.

ID	Name	Product	Family	Severity
79449	OracleVM 2.1 : xen (OVMSA-2008-2007)	Nessus	OracleVM Local Security Checks	medium
67749	Oracle Linux 5 : xen (ELSA-2008-0892)	Nessus	Oracle Linux Local Security Checks	high
60480	Scientific Linux Security Update : xen on SL5.x i386/x86_64	Nessus	Scientific Linux Local Security Checks	medium
43711	CentOS 5 : xen (CESA-2008:0892)	Nessus	CentOS Local Security Checks	medium
40302	openSUSE Security Update : qemu (qemu-691)	Nessus	SuSE Local Security Checks	high
40118	openSUSE Security Update : qemu (qemu-691)	Nessus	SuSE Local Security Checks	high
38777	Ubuntu 8.04 LTS : kvm regression (USN-776-2)	Nessus	Ubuntu Local Security Checks	high
38759	Ubuntu 8.04 LTS / 8.10 : kvm vulnerabilities (USN-776-1)	Nessus	Ubuntu Local Security Checks	high
38747	Debian DSA-1799-1 : qemu - several vulnerabilities	Nessus	Debian Local Security Checks	high
37509	Mandriva Linux Security Advisory : qemu (MDVSA-2008:162)	Nessus	Mandriva Local Security Checks	high
36082	openSUSE 10 Security Update : qemu (qemu-6123)	Nessus	SuSE Local Security Checks	high
34329	RHEL 5 : xen (RHSA-2008:0892)	Nessus	Red Hat Local Security Checks	medium

Detections

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CVE-2008-1945

critical

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medium