CVE-2021-40523 : Security Advisory and Response

This CVE article discusses a vulnerability in Contiki 3.0 related to Telnet option negotiation mishandling, potentially leading to denial of service.

Understanding CVE-2021-40523

A detailed overview of the vulnerability in Contiki 3.0.

What is CVE-2021-40523?

In Contiki 3.0, improper handling of Telnet option negotiation can cause servers to fail in responding to certain commands due to buffer space exhaustion, resulting in denial of service.

The Impact of CVE-2021-40523

The vulnerability can lead to property violations and denial of service when servers fail to respond to specific commands during option negotiation.

Technical Details of CVE-2021-40523

Insight into the technical aspects of the vulnerability in Contiki 3.0.

Vulnerability Description

Servers may not respond to certain commands during Telnet option negotiation due to buffer space exhaustion, causing denial of service.

Affected Systems and Versions

Product: Contiki
Version: 3.0
Status: Affected

Exploitation Mechanism

Improper handling of exception conditions exhausts buffer space, leading to servers failing to respond to essential commands.

Mitigation and Prevention

Ways to mitigate and prevent the impacts of CVE-2021-40523.

Immediate Steps to Take

Monitor Contiki systems for signs of excessive buffer space usage.
Implement network-level protections to filter out malicious Telnet requests.
Consider limiting Telnet access to critical systems.

Long-Term Security Practices

Regularly update Contiki software to patched versions.
Conduct security assessments to identify and address vulnerabilities proactively.

Patching and Updates

Apply patches provided by Contiki to address the Telnet option negotiation mishandling vulnerability.