Multiple TCP/IP stack flaws could leave millions of devices open to attack

The stacks are susceptible to Mitnick attacks

padlock on a binary code background

Security researchers have discovered vulnerabilities in multiple TCP/IP stacks that affect millions of internet-connected devices and could enable hackers to hijack them.

Researchers at Forescout, a cyber security firm, have uncovered nine exploits, dubbed “Number:jack,“ in multiple TCP/IP stacks that improperly generate Initial Sequence Numbers (ISNs) within TCP connections. This meant the flaws left devices’ TCP connections open to attacks. ISNs ensure that every TCP connection between two devices is unique and that there are no collisions so that third parties cannot interfere with an ongoing connection.

The stacks are susceptible to the so-called “Mitnick attack,” named after legendary computer hacker Kevin Mitnick. 

In total, 11 stacks were analyzed: uIP, FNET, picoTCP, Nut/Net, lwIP, cycloneTCP, uC/TCP-IP, MPLAB Net, TI-NDKTCPIP, Nanostack, and Nucleus NET. Millions of devices, including everything from IT file servers to IoT embedded components, use uIP, FNET, picoTCP and Nut/Net. Researchers found improperly generated ISNs in nine of the 11 stacks analyzed.

Researchers said they disclosed the vulnerabilities to the affected vendors and maintainers in October 2020. 

“Most vendors have already issued patches and/or mitigation recommendations to users. The developers of Nut/Net are working on a solution, and Forescout has not received a response from the uIP developers,” the report added.

Researchers have released an open-source script that uses active fingerprinting to detect devices running the affected stacks to help deal with the problem. They also urged organizations to monitor progressive patches released by affected device vendors and devise a remediation plan for their vulnerable asset inventory.

For vulnerable IoT and OT devices, researchers said to use segmentation to minimize network exposure and the likelihood of compromise without impacting mission-critical functions or business operations. “Segmentation and zoning can also limit the blast radius and business impact if a device is compromised,” they added.

David Kennefick, product architect at Edgescan, told ITPro there needs to be a hard think about the technology being implemented in the IoT world. 

“Secure design needs to be implemented from the device inception phase, the technology should be created with a support period in mind with an EOL (end of life) plan, if this doesn’t happen, we will keep finding the same issues in the same stacks for the next 20 years. The broad usage of these devices means a security concern can quickly turn into a safety concern,” he said.

Featured Resources

Preparing for AI-enabled cyber attacks

MIT technology review insights

Download now

Cloud storage performance analysis

Storage performance and value of the IONOS cloud Compute Engine

Download now

The Forrester Wave: Top security analytics platforms

The 11 providers that matter most and how they stack up

Download now

Harness data to reinvent your organisation

Build a data strategy for the next wave of cloud innovation

Download now

Recommended

McAfee’s zero trust solution strengthens private applications’ security
cyber security

McAfee’s zero trust solution strengthens private applications’ security

3 Aug 2021
Senate report slams agencies for poor cyber security
cyber security

Senate report slams agencies for poor cyber security

3 Aug 2021
Mastering endpoint security implementation
Security

Mastering endpoint security implementation

3 Aug 2021
86% of organizations expect a cyber attack in the next 12 months
cyber attacks

86% of organizations expect a cyber attack in the next 12 months

3 Aug 2021

Most Popular

RMIT to be first Australian university to implement AWS supercomputing facility
high-performance computing (HPC)

RMIT to be first Australian university to implement AWS supercomputing facility

28 Jul 2021
Square to acquire Afterpay for $29 billion
mergers and acquisitions

Square to acquire Afterpay for $29 billion

2 Aug 2021
Zyxel USG Flex 200 review: A timely and effective solution
Security

Zyxel USG Flex 200 review: A timely and effective solution

28 Jul 2021