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CentOS 5 : kernel (CESA-2012:0721)

high Nessus Plugin ID 59479

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Synopsis

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

Description

Updated kernel packages that fix two security issues are now available for Red Hat Enterprise Linux 5.

The Red Hat Security Response Team has rated this update as having important security impact. Common Vulnerability Scoring System (CVSS) base scores, which give detailed severity ratings, are available for each vulnerability from the CVE links in the References section.

The kernel packages contain the Linux kernel, the core of any Linux operating system.

This update fixes the following security issues :

* It was found that the Xen hypervisor implementation as shipped with Red Hat Enterprise Linux 5 did not properly restrict the syscall return addresses in the sysret return path to canonical addresses. An unprivileged user in a 64-bit para-virtualized guest, that is running on a 64-bit host that has an Intel CPU, could use this flaw to crash the host or, potentially, escalate their privileges, allowing them to execute arbitrary code at the hypervisor level. (CVE-2012-0217, Important)

* It was found that guests could trigger a bug in earlier AMD CPUs, leading to a CPU hard lockup, when running on the Xen hypervisor implementation. An unprivileged user in a 64-bit para-virtualized guest could use this flaw to crash the host. Warning: After installing this update, hosts that are using an affected AMD CPU (refer to Red Hat Bugzilla bug #824966 for a list) will fail to boot. In order to boot such hosts, the new kernel parameter, allow_unsafe, can be used ('allow_unsafe=on'). This option should only be used with hosts that are running trusted guests, as setting it to 'on' reintroduces the flaw (allowing guests to crash the host). (CVE-2012-2934, Moderate)

Note: For Red Hat Enterprise Linux guests, only privileged guest users can exploit the CVE-2012-0217 and CVE-2012-2934 issues.

Red Hat would like to thank the Xen project for reporting these issues. Upstream acknowledges Rafal Wojtczuk as the original reporter of CVE-2012-0217.

Users should upgrade to these updated packages, which contain backported patches to correct these issues. The system must be rebooted for this update to take effect.

Solution

Update the affected kernel packages.

See Also

http://www.nessus.org/u?fe9573fb

Plugin Details

Severity: High

ID: 59479

File Name: centos_RHSA-2012-0721.nasl

Version: 1.17

Type: local

Agent: unix

Published: 6/14/2012

Updated: 1/4/2021

Supported Sensors: Agentless Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, Nessus

Risk Information

VPR

Risk Factor: Critical

Score: 9.7

CVSS v2

Risk Factor: High

Base Score: 7.2

Temporal Score: 6.3

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

CVSS Score Source: CVE-2012-0217

Vulnerability Information

CPE: p-cpe:/a:centos:centos:kernel-pae, p-cpe:/a:centos:centos:kernel-headers, p-cpe:/a:centos:centos:kernel-debug, p-cpe:/a:centos:centos:kernel-xen, p-cpe:/a:centos:centos:kernel, p-cpe:/a:centos:centos:kernel-doc, p-cpe:/a:centos:centos:kernel-debug-devel, cpe:/o:centos:centos:5, p-cpe:/a:centos:centos:kernel-devel, p-cpe:/a:centos:centos:kernel-pae-devel, p-cpe:/a:centos:centos:kernel-xen-devel

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

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 6/12/2012

Vulnerability Publication Date: 6/12/2012

Exploitable With

CANVAS (CANVAS)

Core Impact

Metasploit (FreeBSD Intel SYSRET Privilege Escalation)

Reference Information

CVE: CVE-2012-0217, CVE-2012-2934

BID: 53961

RHSA: 2012:0721