CVE-2023-31137 : Vulnerability Insights and Analysis

A detailed overview of the MaraDNS Integer Underflow Vulnerability in DNS Packet Decompression.

Understanding CVE-2023-31137

This section explores the specifics of the CVE-2023-31137 vulnerability affecting MaraDNS.

What is CVE-2023-31137?

MaraDNS, an open-source software implementing the Domain Name System (DNS), is impacted by an integer underflow vulnerability in the DNS packet decompression function. This vulnerability, present in version 3.5.0024 and earlier, enables remote attackers to trigger a Denial of Service (DoS) attack by causing abnormal program termination.

The Impact of CVE-2023-31137

The vulnerability arises due to a flaw in the

Decompress.c

file, specifically within the

decomp_get_rddata

function. By exploiting this weakness, threat actors can exploit a DNS packet with certain characteristics, leading to the program's abrupt termination and DoS condition.

Technical Details of CVE-2023-31137

Explore the technical intricacies of CVE-2023-31137 concerning MaraDNS.

Vulnerability Description

In handling a DNS packet with an Answer RR of qtype 16 (TXT record) and any qclass, if the

rdlength

is smaller than

rdata

, a negative number is produced, leading to abnormal memory allocation. This allocation issue ultimately results in a DoS condition.

Affected Systems and Versions

The vulnerability affects MaraDNS versions up to 3.5.0024, making systems running these versions susceptible to exploitation.

Exploitation Mechanism

Threat actors can exploit the integer underflow vulnerability by crafting a specific DNS packet to trigger the flaw, causing the program to terminate unexpectedly.

Mitigation and Prevention

Learn about the necessary steps to mitigate the risks posed by CVE-2023-31137.

Immediate Steps to Take

To address the vulnerability, users are advised to apply the patch introduced in version 3.5.0036 via commit bab062bde40b2ae8a91eecd522e84d8b993bab58.

Long-Term Security Practices

Maintaining up-to-date software versions and implementing secure coding practices are crucial for preventing similar vulnerabilities in the future.

Patching and Updates

Regularly updating MaraDNS to the latest versions and promptly applying security patches is essential for safeguarding systems against potential exploits.