The virNetServerProgramDispatchCall function in libvirt before 0.10.2 allows remote attackers to cause a denial of service (NULL pointer dereference and segmentation fault) via an RPC call with (1) an event as the RPC number or (2) an RPC number whose value is in a "gap" in the RPC dispatch table.

libvirt was updated to fix some bugs and security issues :

Security issues fixed :

  - Fix crash on error paths of message dispatching,     CVE-2013-0170 bnc#800976

  - security: Fix libvirtd crash possibility CVE-2012-4423     bnc#780432

Also bugs were fixed :

  - qemu: Fix probing for guest capabilities bnc#772586

  - xen-xm: Generate UUID if not specified bnc#773626

  - xenParseXM: don't dereference NULL pointer when script     is empty bnc#773621

From Red Hat Security Advisory 2012:1359 :

Updated libvirt packages that fix one security issue and multiple bugs are now available for Red Hat Enterprise Linux 6.

The Red Hat Security Response Team has rated this update as having moderate security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link in the References section.

The libvirt library is a C API for managing and interacting with the virtualization capabilities of Linux and other operating systems. In addition, libvirt provides tools for remote management of virtualized systems.

A flaw was found in libvirtd's RPC call handling. An attacker able to establish a read-only connection to libvirtd could use this flaw to crash libvirtd by sending an RPC message that has an event as the RPC number, or an RPC number that falls into a gap in the RPC dispatch table. (CVE-2012-4423)

This issue was discovered by Wenlong Huang of the Red Hat Virtualization QE Team.

This update also fixes the following bugs :

* When the host_uuid option was present in the libvirtd.conf file, the augeas libvirt lens was unable to parse the file. This bug has been fixed and the augeas libvirt lens now parses libvirtd.conf as expected in the described scenario. (BZ#858988)

* Disk hot plug is a two-part action: the qemuMonitorAddDrive() call is followed by the qemuMonitorAddDevice() call. When the first part succeeded but the second one failed, libvirt failed to roll back the first part and the device remained in use even though the disk hot plug failed. With this update, the rollback for the drive addition is properly performed in the described scenario and disk hot plug now works as expected. (BZ#859376)

* When a virtual machine was started with an image chain using block devices and a block rebase operation was issued, the operation failed on completion in the blockJobAbort() function. This update relabels and configures cgroups for the backing files and the rebase operation now succeeds. (BZ#860720)

All users of libvirt are advised to upgrade to these updated packages, which contain backported patches to correct these issues. After installing the updated packages, libvirtd will be restarted automatically.

Wenlong Huang discovered that libvirt incorrectly handled certain RPC calls. A remote attacker could exploit this and cause libvirt to crash, resulting in a denial of service. This issue only affected Ubuntu 12.04 LTS. (CVE-2012-4423)

Tingting Zheng discovered that libvirt incorrectly handled cleanup under certain error conditions. A remote attacker could exploit this and cause libvirt to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2013-0170).

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.

libvirt received security and bugfixes :

  - Fixed a libvirt remote denial of service (crash)     problem. The following bugs have been fixed :.
    (CVE-2012-4423)

  - qemu: Fix probing for guest capabilities

  - xen-xm: Generate UUID if not specified

  - xenParseXM: don't dereference NULL pointer when script     is empty

- Rebased to version 0.9.6.3

    - CVE-2012-4423 Fix null dereference (bz #857135, bz       #857133)

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.

- Rebased to version 0.9.11.6

    - Fix LXC domain startup with selinux=disabled (bz       #858104)

    - CVE-2012-4423 Fix null dereference (bz #857135, bz       #857133)

    - dnsmasq: avoid forwarding queries without a domain (bz       #849787)

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.

Updated libvirt packages that fix one security issue and multiple bugs are now available for Red Hat Enterprise Linux 6.

The Red Hat Security Response Team has rated this update as having moderate security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link in the References section.

The libvirt library is a C API for managing and interacting with the virtualization capabilities of Linux and other operating systems. In addition, libvirt provides tools for remote management of virtualized systems.

A flaw was found in libvirtd's RPC call handling. An attacker able to establish a read-only connection to libvirtd could use this flaw to crash libvirtd by sending an RPC message that has an event as the RPC number, or an RPC number that falls into a gap in the RPC dispatch table. (CVE-2012-4423)

This issue was discovered by Wenlong Huang of the Red Hat Virtualization QE Team.

This update also fixes the following bugs :

* When the host_uuid option was present in the libvirtd.conf file, the augeas libvirt lens was unable to parse the file. This bug has been fixed and the augeas libvirt lens now parses libvirtd.conf as expected in the described scenario. (BZ#858988)

* Disk hot plug is a two-part action: the qemuMonitorAddDrive() call is followed by the qemuMonitorAddDevice() call. When the first part succeeded but the second one failed, libvirt failed to roll back the first part and the device remained in use even though the disk hot plug failed. With this update, the rollback for the drive addition is properly performed in the described scenario and disk hot plug now works as expected. (BZ#859376)

* When a virtual machine was started with an image chain using block devices and a block rebase operation was issued, the operation failed on completion in the blockJobAbort() function. This update relabels and configures cgroups for the backing files and the rebase operation now succeeds. (BZ#860720)

All users of libvirt are advised to upgrade to these updated packages, which contain backported patches to correct these issues. After installing the updated packages, libvirtd will be restarted automatically.

The libvirt library is a C API for managing and interacting with the virtualization capabilities of Linux and other operating systems. In addition, libvirt provides tools for remote management of virtualized systems.

A flaw was found in libvirtd's RPC call handling. An attacker able to establish a read-only connection to libvirtd could use this flaw to crash libvirtd by sending an RPC message that has an event as the RPC number, or an RPC number that falls into a gap in the RPC dispatch table. (CVE-2012-4423)

This update also fixes the following bugs :

  - When the host_uuid option was present in the     libvirtd.conf file, the augeas libvirt lens was unable     to parse the file. This bug has been fixed and the     augeas libvirt lens now parses libvirtd.conf as expected     in the described scenario.

  - Disk hot plug is a two-part action: the     qemuMonitorAddDrive() call is followed by the     qemuMonitorAddDevice() call. When the first part     succeeded but the second one failed, libvirt failed to     roll back the first part and the device remained in use     even though the disk hot plug failed. With this update,     the rollback for the drive addition is properly     performed in the described scenario and disk hot plug     now works as expected.

  - When a virtual machine was started with an image chain     using block devices and a block rebase operation was     issued, the operation failed on completion in the     blockJobAbort() function. This update relabels and     configures cgroups for the backing files and the rebase     operation now succeeds.

After installing the updated packages, libvirtd will be restarted automatically.

The remote Redhat Enterprise Linux 6 host has packages installed that are affected by a vulnerability as referenced in the RHSA-2012:1359 advisory.

  - libvirt: null function pointer invocation in virNetServerProgramDispatchCall() (CVE-2012-4423)

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

ID	Name	Product	Family	Severity
74880	openSUSE Security Update : libvirt (openSUSE-SU-2013:0274-1)	Nessus	SuSE Local Security Checks	high
68637	Oracle Linux 6 : libvirt (ELSA-2012-1359)	Nessus	Oracle Linux Local Security Checks	medium
64289	Ubuntu 12.04 LTS / 12.10 : libvirt vulnerabilities (USN-1708-1)	Nessus	Ubuntu Local Security Checks	high
64201	SuSE 11.2 Security Update : libvirt (SAT Patch Number 7015)	Nessus	SuSE Local Security Checks	medium
62569	Fedora 16 : libvirt-0.9.6.3-1.fc16 (2012-15640)	Nessus	Fedora Local Security Checks	medium
62551	Fedora 17 : libvirt-0.9.11.6-1.fc17 (2012-15634)	Nessus	Fedora Local Security Checks	medium
62520	CentOS 6 : libvirt (CESA-2012:1359)	Nessus	CentOS Local Security Checks	medium
62506	Scientific Linux Security Update : libvirt on SL6.x i386/x86_64 (20121011)	Nessus	Scientific Linux Local Security Checks	medium
62505	RHEL 6 : libvirt (RHSA-2012:1359)	Nessus	Red Hat Local Security Checks	critical

Detections

Analytics

CVE-2012-4423

critical

Tenable Plugins

high

medium

high

medium

medium

medium

medium

medium

critical