First Published: September 12, 2018
 

Impact of Vulnerability:	CWE-controlled release: Uncontrolled Resource Consumption ('Resource Exhaustion')
CVE ID	CVE-2018-5390
Severity Rating	High
CVSS v3 Base Score	7.5
Recommendations:	Deploy product updates as they are made available.
Affected Software:	Advanced Threat Defense (ATD) Data Exchange Layer (DXL) Data Loss Prevention (DLP) Monitor Data Loss Prevention (DLP) Prevent McAfee Active Response (MAR) McAfee Email Gateway (MEG) McAfee Linux Operating System (MLOS) McAfee Web Gateway (MWG) Network Security Manager (NSM) Linux SIEM Threat Intelligence Exchange (TIE) Server
Location of updated software:	Product Downloads site

 
Article contents:

• Vulnerability Description
• Product Vulnerability Status
• Remediation
• Product-Specific Notes
• Workaround
• Mitigations
• Acknowledgements
• Frequently Asked Questions (FAQs)
• Resources
• Disclaimer

Vulnerability Description
A Linux kernel flaw known as SegmentSmack allows remote attackers to cause a denial-of-service using specially crafted TCP packets. A continuous two-way TCP session to a reachable open port is required to maintain the denial-of-service condition, so a spoofed IP address cannot be used to carry out the attack.

CVE-2018-5390
Linux kernel versions 4.9+ can be forced to make expensive calls to tcp_collapse_ofo_queue() and tcp_prune_ofo_queue() for every incoming packet, which can lead to a denial-of-service.
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-5390
https://nvd.nist.gov/vuln/detail/CVE-2018-5390

Product Vulnerability Status
We produce several security appliances that ship with a Linux operating system. These appliances are potentially vulnerable to the kernel flaw described in this Security Bulletin. Investigation into all our products is ongoing. This Security Bulletin will be updated as additional information is available. Not every version of the "Vulnerable and Updated" products are vulnerable. See the Product-Specific Notes section below for details. Products not on these lists are being investigated. 
 
Vulnerable and Updated

• Advanced Threat Defense (ATD)
• Data Exchange Layer (DXL)
• McAfee Active Response (MAR)
• McAfee Linux Operating System (MLOS)
• Network Security Manager (NSM) Linux
• McAfee Web Gateway (MWG)
• Data Loss Prevention (DLP) Monitor
• Data Loss Prevention (DLP) Prevent
• SIEM
• Threat Intelligence Exchange (TIE) Server

Not Vulnerable

• Data Loss Prevention Endpoint (DLP Endpoint) / Host Data Loss Prevention (HDLP)
• Endpoint Security (ENS)
• ePolicy Orchestrator (ePO)
• Host Intrusion Prevention Services (Host IPS)
• McAfee Agent (MA)
• McAfee Email Gateway (MEG)
• Network Security Platform (NSP) Azure VM
• Network Security Platform (NSP) Hardware Appliances
• Network Threat Behavior Analysis (NTBA)
• VirusScan Enterprise for Storage (VSES)
• Other products that do not ship with a Linux operating system

Remediation
To remediate this issue, go to the Product Downloads site and download the applicable product update/hotfix files:
 

Product	Versions	Type	File Name	Release Date
ATD	4.6.0	Update	migration-4.6.0.21.517580.msu	November 13, 2018
DXL	5.0.1	Update	DXL Platform 5.0.1 Version 5.0.1.198.1	February 26, 2019
DXL	4.1.2 Hotfix 1 (HF1)	Hotfix	DXL Platform 4.1.2 HF1 Version 4.1.2.115	January 23, 2019
MAR	MAR 2.3.0 HF3 (MAR Server Bundle version 2.3.0.171 - includes MAR Server and Platform packages 2.3.0.243)	Hotfix	MAR-Server-Bundle_2.3.0_Build_171_(ENU-RELEASE-MAIN).zip	September 4, 2018
MLOS2	MLOS2 kernel-4.9.116	Maintenance Release	kernel-4.9.116-1.mlos2.x86_64.rpm	August 3, 2018
MLOS3	MLOS3 kernel-4.9.116	Maintenance Release	kernel-4.9.116-1.mlos3.x86_64.rpm	August 3, 2018
MWG	7.7.2.17 build 26804	Main Release	mwgappl-7.7.2.17.0-26803-x.86_64.iso	September 11, 2018
MWG	7.8.2.2 build 26803	General Availability	mwgappl-7.8.2.2.0-26805-x.86_64.iso	September 11, 2018
DLP Monitor	11.0.600-3489.103	Update	McAfee-MS-11.0.600-3489.103.iso	October 2, 2018
DLP Prevent	11.0.600-3489.103	Update	McAfee-PS-11.0.600-3489.103.iso	October 2, 2018
NSM Linux	NSM_MLOS-3.5.0.9465_V1 Version 3.30	Hotfix	NSM_MLOS-3.5.0.9465_V1.bsx	August 31, 2018
SIEM	10.3.3	Update	NOTE: Choose the correct file for the appliance type. ESSREC_Update_10.3.3.signed.tgz ESS_Update_10.3.3.signed.tgz RECEIVER_Update_10.3.3.signed.tgz APM_Update_10.3.3.signed.tgz DBM_Update_10.3.3.signed.tgz	November 13, 2018
TIE Server	TIE Server 2.3.0	General Availability	TIEServer_2.3.0.328_MARServer_2.4.0.158.x86_64-MAIN.ova	September 25, 2018

 
Download and Installation Instructions
For instructions to download product updates and hotfixes, see KB56057 - How to download Enterprise product updates and documentation. Review the Release Notes and the Installation Guide for instructions on how to install these updates. All documentation is available on the Product Documentation site.

Product-Specific Notes
MLOS2/ MLOS3:
In addition to the kernel updates, the packages include Intel^® Microcode updates:
microcode   = (MLOS2) intel-ucode-20180807-2.mlos2.x86_64.rpm
                     = (MLOS3) intel-ucode-20180807-2.mlos3.x86_64.rpm
 
Kernel and microcode updates must both be applied. The above are the minimum versions for the fixes, but when updating, always take the latest package.

Network Security Platform:
Network Security Platform Hardware Appliances are not vulnerable. The recommendation for all Network Security Platform Virtual deployments is for the underlying host systems to be updated. Network Security Manager Linux appliance is vulnerable and requires the MLOS version hotfix indicated in the remediation table.

Workaround
To mitigate SegmentSmack, you can add the following to your bootup process:
 
## turn on mitigation
$ SetSmack.sh low
## this is the script
$ cat SetSmack.sh
#!/bin/sh
if [ "x$1" == "xlow" ]; then
    echo Setting limits low:
    sysctl -w net.ipv4.ipfrag_low_thresh=196608
    sysctl -w net.ipv4.ipfrag_high_thresh=262144
    sysctl -w net.ipv6.ip6frag_low_thresh=196608
    sysctl -w net.ipv6.ip6frag_high_thresh=262144
    echo
elif [ "x$1" == "xdef" ]; then
    echo Setting limits default:
    sysctl -w net.ipv4.ipfrag_high_thresh=4194304
    sysctl -w net.ipv4.ipfrag_low_thresh=3145728
    sysctl -w net.ipv6.ip6frag_high_thresh=4194304
    sysctl -w net.ipv6.ip6frag_low_thresh=3145728
    echo
fi
echo Current values:
sysctl net.ipv4.ipfrag_low_thresh
sysctl net.ipv4.ipfrag_high_thresh
sysctl net.ipv6.ip6frag_low_thresh
sysctl net.ipv6.ip6frag_high_thresh

Mitigations
No vulnerability detection signatures are available.

Acknowledgements
This vulnerability was disclosed by The MITRE Corporation as a CVE.

Frequently Asked Questions (FAQs)
How do I know if my product is vulnerable?
 
For Endpoint products:
Use the following instructions for endpoint or client-based products:

1. Right-click on the McAfee tray shield icon on the Windows taskbar.
2. Select Open Console.
3. In the console, select Action Menu.
4. In the Action Menu, select Product Details. The product version is displayed.

For ePO/Server products:
Use the following instructions for server-based products:

• Check the version and build of ePO that is installed. For information about how to check the version, see: KB52634.
• Create a query in ePO for the product version of the product installed within your organization.

For Appliances:
Use the following instructions for Appliance-based products:

1. Open the Administrator's User Interface (UI).
2. Click the About link. The product version is displayed.

For DLP Endpoint ePO Extension:
Use the following instructions:

1. Log on to your ePO server.
2. Click Menu, Data Protection, DLP Policy.
3. Inside the DLP console click Help, About. The product version is displayed.

What is CVSS?
CVSS, or Common Vulnerability Scoring System, is the result of the National Infrastructure Advisory Council's effort to standardize a system of assessing the criticality of a vulnerability. This system offers an unbiased criticality score between 0 and 10 that customers can use to judge how critical a vulnerability is and plan accordingly. For more information, visit the CVSS website at: http://www.first.org/cvss/.
 
When calculating CVSS scores, we've adopted a philosophy that fosters consistency and repeatability. Our guiding principle for CVSS scoring is to score the exploit under consideration by itself. We consider only the immediate and direct impact of the exploit under consideration. We do not factor into a score any potential follow-on exploits that might be made possible by the successful exploitation of the issue being scored.
 
What are the CVSS scoring metrics?

CVE-2018-5390: SegmentSmack
 

Base Score	7.5
Attack Vector (AV)	Network (N)
Attack Complexity (AC)	Low (L)
Privileges Required (PR)	None (N)
User Interaction (UI)	None (N)
Scope (S)	Unchanged (U)
Confidentiality (C)	None (N)
Integrity (I)	None (N)
Availability (A)	High (H)

 
NOTE: The below CVSS version 3.0 vector was used to generate this score.
https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
 
Where can I find a list of all Security Bulletins?
All Security Bulletins are published on our Knowledge Center. Security Bulletins are retired (removed) once a product is both End of Sale and End of Support (End of Life).
 
How do I report a product vulnerability to you?
If you have information about a security issue or vulnerability with a product, follow the instructions provided in KB95563 - Report a vulnerability.
 
How do you respond to this and any other reported security flaws?
Our key priority is the security of our customers. If a vulnerability is found within any of our software or services, we work closely with the relevant security software development team to ensure the rapid and effective development of a fix and communication plan.
 
We only publish Security Bulletins if they include something actionable such as a workaround, mitigation, version update, or hotfix. Otherwise, we would simply be informing the hacker community that our products are a target, putting our customers at greater risk. For products that are updated automatically, a non-actionable Security Bulletin might be published to acknowledge the discoverer.
 
To view our PSIRT policy, see KB95564 - About PSIRT.
 
Resources

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Disclaimer
The information provided in this Security Bulletin is provided as is without warranty of any kind. We disclaim all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall we or our suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits, or special damages, even if we or our suppliers have been advised of the possibility of such damages. Some states don't allow the exclusion or limitation of liability for consequential or incidental damages, so the preceding limitation may not apply.

Any future product release dates mentioned in this Security Bulletin are intended to outline our general product direction, and they shouldn't be relied on in making a purchasing decision. The product release dates are for information purposes only, and may not be incorporated into any contract. The product release dates aren't a commitment, promise, or legal obligation to deliver any material, code, or functionality. The development, release, and timing of any features or functionality described for our products remain at our sole discretion and may be changed or canceled at any time.