CVE-2020-24339 : Exploit Details and Defense Strategies

An issue was discovered in picoTCP and picoTCP-NG through 1.7.0, leading to Denial-of-Service due to out-of-bounds reads in the DNS domain name record decompression functionality.

Understanding CVE-2020-24339

This CVE involves a vulnerability in picoTCP and picoTCP-NG versions up to 1.7.0, impacting the DNS domain name record decompression functionality.

What is CVE-2020-24339?

The issue arises from the lack of validation of compression pointer offset values in the DNS response packet, allowing for out-of-bounds reads that can result in a Denial-of-Service attack.

The Impact of CVE-2020-24339

The vulnerability can be exploited to cause a Denial-of-Service condition, potentially disrupting network services and availability.

Technical Details of CVE-2020-24339

This section provides more in-depth technical insights into the CVE.

Vulnerability Description

The problem lies in the DNS domain name record decompression functionality in pico_dns_decompress_name() in pico_dns_common.c, where inadequate validation of compression pointer offset values leads to out-of-bounds reads.

Affected Systems and Versions

picoTCP and picoTCP-NG versions up to 1.7.0

Exploitation Mechanism

Attackers can exploit this vulnerability by crafting malicious DNS response packets with specific compression pointer offset values to trigger out-of-bounds reads.

Mitigation and Prevention

Protecting systems from CVE-2020-24339 requires immediate actions and long-term security measures.

Immediate Steps to Take

Apply vendor patches or updates promptly to address the vulnerability.
Monitor network traffic for any signs of exploitation.

Long-Term Security Practices

Regularly update and patch all software components to prevent known vulnerabilities.
Implement network segmentation and access controls to limit the impact of potential attacks.

Patching and Updates

Check for security advisories from picoTCP and picoTCP-NG for patches addressing CVE-2020-24339.