1. Overview:

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

This update fixes the following security issues:

* A NULL pointer dereference flaw was found in the Linux kernel's Stream Control Transmission Protocol (SCTP) implementation. A remote attacker could send a specially-crafted SCTP packet to a target system, resulting in a denial of service. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2011-2482 to this issue.

* A flaw in the Linux kernel's client-side NFS Lock Manager (NLM) implementation could allow a local, unprivileged user to cause a denial of service. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2011-2491 to this issue.

* Buffer overflow flaws in the Linux kernel's netlink-based wireless configuration interface implementation could allow a local user, who has the CAP_NET_ADMIN capability, to cause a denial of service or escalate their privileges on systems that have an active wireless interface. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2011-2517 to this issue.

* A flaw was found in the way the Linux kernel's Xen hypervisor implementation emulated the SAHF instruction. When using a fully-virtualized guest on a host that does not use hardware assisted paging (HAP), such as those running CPUs that do not have support for (or those that have it disabled) Intel Extended Page Tables (EPT) or AMD Virtualization (AMD-V) Rapid Virtualization Indexing (RVI), a privileged guest user could trigger this flaw to cause the hypervisor to crash. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2011-2519 to this issue.

* An off-by-one flaw was found in the __addr_ok() macro in the Linux kernel's Xen hypervisor implementation when running on 64-bit systems. A privileged guest user could trigger this flaw to cause the hypervisor to crash. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2011-2901 to this issue.

* /proc/[PID]/io is world-readable by default. Previously, these files could be read without any further restrictions. A local, unprivileged user could read these files, belonging to other, possibly privileged processes to gather confidential information, such as the length of a password used in a process. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2011-2495 to this issue.

More information about these vulnerabilities can be found in the security advisory issued by Red Hat:

• https://rhn.redhat.com/errata/RHSA-2011-1212.html
• https://rhn.redhat.com/errata/RHSA-2011-1813.html

2. Avaya System Products using a modified version of RHEL5 with affected components/packages installed:

Recommended Actions for System Products:
Avaya strongly recommends that customers follow networking and security best practices by implementing firewalls, ACLs, physical security or other appropriate access restrictions. Though Avaya believes such restrictions should always be in place, risk to Avaya products and the surrounding network from this potential vulnerability may be mitigated by ensuring these practices are implemented until such time as an Avaya provided product update or the recommended Avaya action is applied. Further restrictions as deemed necessary based on the customer's security policies may be required during this interim period, but customers should not modify the System Product operating system or application unless the change is approved by Avaya. Making changes that are not approved may void the Avaya product service contract.

Mitigating Factors:

When determining risk, Avaya takes into account many factors as outlined by Avaya's Security Vulnerability Classification Policy. The following table describes factors that mitigate the risk of specific vulnerabilities for affected Avaya products:

3. Avaya Software-Only Products:

Avaya software-only products operate on general-purpose operating systems. Occasionally vulnerabilities may be discovered in the underlying operating system or applications that come with the operating system. These vulnerabilities often do not impact the software-only product directly but may threaten the integrity of the underlying platform.

In the case of this advisory Avaya software-only products are not affected by the vulnerability directly but the underlying Linux platform may be. Customers should determine on which Linux operating system the product was installed and then follow that vendor's guidance.

Recommended Actions for Software-Only Products:
In the event that the affected package is installed, Avaya recommends that customers follow recommended actions supplied by Red Hat regarding their Enterprise Linux.

4. Additional Information:

Additional information may also be available via the Avaya support website and through your Avaya account representative. Please contact your Avaya product support representative, or dial 1-800-242-2121, with any questions.

5. Disclaimer:

ALL INFORMATION IS BELIEVED TO BE CORRECT AT THE TIME OF PUBLICATION AND IS PROVIDED "AS IS". AVAYA INC., ON BEHALF ITSELF AND ITS SUBSIDIARIES AND AFFILIATES (HEREINAFTER COLLECTIVELY REFERRED TO AS "AVAYA"), DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE AND FURTHERMORE, AVAYA MAKES NO REPRESENTATIONS OR WARRANTIES THAT THE STEPS RECOMMENDED WILL ELIMINATE SECURITY OR VIRUS THREATS TO CUSTOMERS' SYSTEMS. IN NO EVENT SHALL AVAYA BE LIABLE FOR ANY DAMAGES WHATSOEVER ARISING OUT OF OR IN CONNECTION WITH THE INFORMATION OR RECOMMENDED ACTIONS PROVIDED HEREIN, INCLUDING DIRECT, INDIRECT, INCIDENTAL, STATUTORY, CONSEQUENTIAL DAMAGES, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF AVAYA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

THE INFORMATION PROVIDED HERE DOES NOT AFFECT THE SUPPORT AGREEMENTS IN PLACE FOR AVAYA PRODUCTS. SUPPORT FOR AVAYA PRODUCTS CONTINUES TO BE EXECUTED AS PER EXISTING AGREEMENTS WITH AVAYA.

6. Revision History:

V 1.0 - November 2, 2011 - Initial Statement issued.
V 2.0 - November 10, 2011 - Changed AES, AS5300, IP Office Application Server, IQ, PC, SP, VP and overall advisory risk level to low. Added more detail to mitigating factors table.
V 3.0 - November 10, 2011 - Corrected CVE in Mitigating Factor Table.
V 4.0 - December 15, 2011 - Added reference to RHSA-2011-1813.
V 5.0 - May 3, 2012 - Updated AES, AS5300, SM and US actions.
V 6.0 - December 5, 2012 - Updated PS actions.
V 7.0 - April 2, 2013 - Updated PC, SMGR, SP, VP and US affected versions and actions.
V 8.0 - August 12, 2015 - Updated affected versions and actions for CM, IPOAS, IQ, Messaging and actions for CS1K, Conferencing SE, and set advisory status to Final.

Send information regarding any discovered security problems with Avaya products to either the contact noted in the product's documentation or securityalerts@avaya.com.

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