Dark Reading is part of the Informa Tech Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them.Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Vulnerabilities / Threats

2/10/2021
06:50 PM
Connect Directly
Twitter
LinkedIn
RSS
E-Mail
50%
50%

High-Severity Vulnerabilities Discovered in Multiple Embedded TCP/IP Stacks

Flaw leaves millions of IT, OT, and IoT devices vulnerable to attack.

A long-known implementation error in the Transmission Control Protocol (TCP) that network devices use to communicate with each other continues to persist in TCP/IP stacks used in millions of IT, OT, and IoT devices.

The vulnerabilities give attackers a way to hijack TCP connections, close them, spoof packets, bypass authentication, and inject data into network traffic. The flaws were discovered in nine out of 11 TCP/IP stacks recently analyzed by Forescout as part of a broader study in recent months of the communication protocol's security.

Related Content:

Understanding TCP/IP Stack Vulnerabilities in the IoT

Special Report: How IT Security Organizations are Attacking the Cybersecurity Problem

New From The Edge: Fighting Fileless Malware, Part 2: Countermeasures

The vulnerabilities—the same across all nine stacks—involve the manner in which the so-called Initial Sequence Number (ISN) is generated.

The ISN ensures that every TCP connection is unique, that there are no collisions with other connections, and that no third party can interfere with an ongoing connection. To guarantee this, the ISN is randomly generated so no one can guess the number and use it to hijack an ongoing connection or spoof a new one.

Forescout's analysis showed problems with the manner in which the TCP/IP stacks that were analyzed generate the ISNs. In nine of the 11 stacks, the ISNs were improperly generated, leaving the connections open to attacks. In some cases, the numbers were predictable, and in others, the problem had to do with the underlying algorithm. In other cases, the numbers had constant increments, while others used a combination of values that could be inferred, Forescout said in its report.

"TCP/IP stacks tend to have many critical vulnerabilities that are widespread," says Daniel dos Santos, research manager at Forescout Research Labs.

The vulnerabilities in general tend not to be related to a specific stack vendor or to a stack being open- or closed source. Rather, the problem has to do with code that was designed and implemented decades ago - that there's been relativley little analysis by the security community in this space. "These vulnerabilities are reminiscent of issues seen and fixed in the IT world—think Linux, Windows, UNIX—a long time ago."

Forescout's study involved seven open-source TCP/IP stacks (uIP, FNET, picoTCP, Nut/Net, lwIP, cycloneTCP, and uC/TCP-IP) and four from commercial vendors: MPLAB Net from Microchip; Texas Instruments' NDKTCPIP, ARM's Nanostack, and Siemens' Nucleus NET. Forescout last October informed the vendors and maintainers of these stacks of the vulnerabilities it had discovered; patches or mitigations have been issued for all the vulnerable stacks except for Nut/Net and uIP.

Second Batch of TCP/IP Vulnerabilities

Forsecout's discovery of the ISN vulnerabilities -- which it is collectively calling Number:Jack -- follows a similar disclosure by the company last year of 33 memory corruption vulnerabilities in TCP/IP implementations in products from 150 vendors. According to the company those vulnerabilities, dubbed Amnesia:33, were more severe than the ISN flaws it announced this week. That's because Amnesia:33 allowed for device compromise, remote code execution, data theft, and denial-of-service attacks.

But Dos Santos says that finding and exploiting ISN generation vulnerabilities is much easier for an attacker than discovering and exploiting memory corruption issues. "[That's] because the analysis of the code is more targeted and the exploitation is similar across devices, regardless of specifics of architecture or memory organization."

The bug discoveries are part of a broader Project Memoria initiative by Forescout to analyze the security of widely used TCP/IP stacks.

"Project Memoria was prompted by us recognizing the foundational nature of embedded TCP/IP stacks in modern devices and the fact that these stacks are often 'ancient' pieces of code that get reused many times over," Dos Santos says. The goal is not just to find new vulnerabilities, but to consolidate the knowledge around these types of issues, he says.

Going into the study, Forescout expected to unearth new vulnerabilities in TCP/IP, but not at the scale it has, he says. What the research has shown is that these stacks have several vulnerabilities and often in the same places.

"We tend to find these 'anti-patterns' repeated over and over again," Dos Santos notes. "The ISN issue is a typical example of a very specific feature that is vulnerable in almost every instance we analyzed."

Affected Devices

In its report this week Forescout pointed to several public use cases of the TCP/IP stacks that the company analyzed, including in medical devices, IT storage systems, wind-turbine monitoring systems, and remote terminal units.

The company says that organizations using devices with these stacks should consider employing encrypted connections and limiting exposure of the devices to the Internet.

To mitigate risk of exposure to these vulns, Forescout recommends using IPSec encrypted connections, limiting the network exposure of critical vulnerable devices, and patching whenever device vendors release advisories. The security vendor also advocates that organizations discover and inventory devices with buggy TCP/IP stacks, and segment their network to minimize damage.

 

Jai Vijayan is a seasoned technology reporter with over 20 years of experience in IT trade journalism. He was most recently a Senior Editor at Computerworld, where he covered information security and data privacy issues for the publication. Over the course of his 20-year ... View Full Bio
 

Recommended Reading:

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
lancop
50%
50%
lancop,
User Rank: Moderator
2/11/2021 | 9:42:40 AM
Another great article from Jai Vijayan
I always appreciate your in-depth & concise security alert articles. They help me to stay on top of emerging exploits.

Having been in IT my entire adult life, I am always sobered by the endless number & variety of computing vulnerabilities that keep cropping up in my profession. It's a painful reminder that the Information Age, where information is supposed to be THE storehouse of economic value, is actually a Wild West free-for-all where theft of valuable data is almost a trivial problem. Certainly easier for the bad guys than actually robbing a bank or physically stealing blueprints for an innovative new product.

What this means for the future is that the real economic value is having the industrial infrastructure to create marketable products from stolen R&D files. And that radically shifts the global economic competitiveness paradigm, doesn't it.
Commentary
Ransomware Is Not the Problem
Adam Shostack, Consultant, Entrepreneur, Technologist, Game Designer,  6/9/2021
Edge-DRsplash-11-edge-ask-the-experts
How Can I Test the Security of My Home-Office Employees' Routers?
John Bock, Senior Research Scientist,  6/7/2021
News
New Ransomware Group Claiming Connection to REvil Gang Surfaces
Jai Vijayan, Contributing Writer,  6/10/2021
Register for Dark Reading Newsletters
White Papers
Video
Cartoon Contest
Write a Caption, Win an Amazon Gift Card! Click Here
Latest Comment: This gives a new meaning to blind leading the blind.
Current Issue
The State of Cybersecurity Incident Response
In this report learn how enterprises are building their incident response teams and processes, how they research potential compromises, how they respond to new breaches, and what tools and processes they use to remediate problems and improve their cyber defenses for the future.
Flash Poll
How Enterprises are Developing Secure Applications
How Enterprises are Developing Secure Applications
Recent breaches of third-party apps are driving many organizations to think harder about the security of their off-the-shelf software as they continue to move left in secure software development practices.
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2021-28815
PUBLISHED: 2021-06-16
Insecure storage of sensitive information has been reported to affect QNAP NAS running myQNAPcloud Link. If exploited, this vulnerability allows remote attackers to read sensitive information by accessing the unrestricted storage mechanism. This issue affects: QNAP Systems Inc. myQNAPcloud Link vers...
CVE-2021-3535
PUBLISHED: 2021-06-16
Rapid7 Nexpose is vulnerable to a non-persistent cross-site scripting vulnerability affecting the Security Console's Filtered Asset Search feature. A specific search criterion and operator combination in Filtered Asset Search could have allowed a user to pass code through the provided search field. ...
CVE-2021-32685
PUBLISHED: 2021-06-16
tEnvoy contains the PGP, NaCl, and PBKDF2 in node.js and the browser (hashing, random, encryption, decryption, signatures, conversions), used by TogaTech.org. In versions prior to 7.0.3, the `verifyWithMessage` method of `tEnvoyNaClSigningKey` always returns `true` for any signature that has a SHA-5...
CVE-2021-32623
PUBLISHED: 2021-06-16
Opencast is a free and open source solution for automated video capture and distribution. Versions of Opencast prior to 9.6 are vulnerable to the billion laughs attack, which allows an attacker to easily execute a (seemingly permanent) denial of service attack, essentially taking down Opencast using...
CVE-2021-32676
PUBLISHED: 2021-06-16
Nextcloud Talk is a fully on-premises audio/video and chat communication service. Password protected shared chats in Talk before version 9.0.10, 10.0.8 and 11.2.2 did not rotate the session cookie after a successful authentication event. It is recommended that the Nextcloud Talk App is upgraded to 9...