kernel security, bug fix, and enhancement update (RHSA-2015-1221)

Original Release Date: September 2, 2015
Last Revised: November 8, 2016
Number: ASA-2015-336
Risk Level: Medium
Advisory Version: 4.0
Advisory Status: Final

1. Overview:

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

A NULL pointer dereference flaw was found in the way the Linux kernel's virtual console implementation handled reference counting when accessing pseudo-terminal device files (/dev/pts/*). A local, unprivileged attacker could use this flaw to crash the system. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2011-5321 to this issue.

It was found that the Linux kernel's ping socket implementation did not properly handle socket unhashing during spurious disconnects, which could lead to a use-after-free flaw. On x86-64 architecture systems, a local user able to create ping sockets could use this flaw to crash the system. On non-x86-64 architecture systems, a local user able to create ping sockets could use this flaw to escalate their privileges on the system. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2015-3636 to this issue.

An integer overflow flaw was found in the way the Linux kernel randomized the stack for processes on certain 64-bit architecture systems, such as x86-64, causing the stack entropy to be reduced by four. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2015-1593 to this issue.

A flaw was found in the way the Linux kernel's 32-bit emulation implementation handled forking or closing of a task with an 'int80' entry. A local user could potentially use this flaw to escalate their privileges on the system. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2015-2830 to this issue.

It was found that the Linux kernel's TCP/IP protocol suite implementation for IPv6 allowed the Hop Limit value to be set to a smaller value than the default one. An attacker on a local network could use this flaw to prevent systems on that network from sending or receiving network packets. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2015-2922 to this issue.

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

2. Avaya System Products using a modified version of RHEL6 with affected packages installed:

Product: Affected Version(s): Risk Level: Actions:
Avaya CMS R17 through R17 R4, R18, R18.0.0.1 Low For R17, upgrade to R17 R5 or later.
For R18 and R18.0.0.1 Upgrade to R18.0.0.2.
Avaya Breeze™ Platform 2.x, 3.x Low Upgrade to 3.1 or later.
Avaya Aura® Conferencing 7.x, 8.0 through 8.0 SP4 Medium Upgrade to 8.0 SP5 or later.
Avaya Aura® Experience Portal 6.x, 7.0, 7.0.1, 7.0.2 Low For 7.0.1 and earlier, upgrade to 7.0.2 and Avaya Linux for 7.0.2, and install Security Update patch 7.0.2.0.1510.
For 7.0.2, install Security Update patch 7.0.2.0.1510 or later.
Avaya IP Office Server Edition 8.1, 9.x Low Upgrade to 10.0 or later.
Avaya IP Office Application Server 9.x Low Upgrade to 10.0 or later.
Avaya one-X® Client Enablement Services 6.2 through 6.2 SP3 Low Upgrade to 6.2 SP4 or later.
Avaya Session Border Controller for Enterprise 6.0.0 through 6.3.4, 7.0 Medium For 6.x, upgrade to 6.3.5 or later.
For 7.0, upgrade to 7.0.1 or later.
Avaya Aura® Session Manager 6.0 through 6.3.15, 7.0 Low For 6.x, upgrade to 6.3.16 or later.
For 7.0, upgrade to 7.0.0.1 or later.

Recommended Actions for System Products:
Avaya strongly recommends following 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 the System Product operating system or application should not be modified 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:

Vulnerability Mitigating Factors
CVE-2011-5321
CVE-2015-3636
This is rated a Medium risk for Conferencing and SBCE because of the potential for an authenticated user to escalate privileges.
These are rated a Low risk for remaining products because the default users on the other systems wouldn't gain any additional privileges.
CVE-2015-1593
These are rated a Low risk for all products because no critical services are affected.
CVE-2015-2830
This is rated a None risk level as all products use a 64 bit OS.
CVE-2015-2922
These are rated a Low risk for all products because IPv6 is not used.

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.

Product: Actions:
Avaya Aura® Experience Portal Depending on the Operating System installed, the affected package may be installed on the underlying Operating System supporting the EP application.

Recommended Actions for Software-Only Products:
In the event that the affected package is installed, Avaya recommends following 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, IS PROVIDED "AS IS", AND IS APPLICABLE ONLY TO PRODUCT VERSIONS ELIGIBLE FOR MANUFACTURER SUPPORT IN ACCORDANCE WITH AVAYA PRODUCT LIFE CYCLE POLICY. 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 - September 2, 2015 - Initial Statement issued.
V 2.0 - February 12, 2016 - Updated affected versions and actions for CMS, CE, SM, One-X CES and EP.
V 3.0 - August 8th, 2016 - Updated affected versions and actions for CMS, Conferencing, and Session Border Controller for Enterprise.
V 4.0 - November 8, 2016 - Updated affected actions for IPOSE and IPOAS, and set advisory status to Final.

Avaya customers or Business Partners should report any security issues found with Avaya products via the standard support process.
Independent security researchers can contact Avaya at [email protected].

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