CVE-2021-37136 Explained : Impact and Mitigation

A vulnerability has been identified in the Bzip2 decompression decoder function within the Netty project, affecting all users of Bzip2Decoder. Malicious input can lead to an Out-Of-Memory Error (OOME) and enable a Denial of Service (DoS) attack.

Understanding CVE-2021-37136

This section provides an insightful look into the nature of the CVE-2021-37136 vulnerability.

What is CVE-2021-37136?

The Bzip2 decompression decoder function lacks size restrictions on output data, impacting decompression allocation sizes and potentially causing an OOME, facilitating DoS attacks.

The Impact of CVE-2021-37136

The vulnerability in Netty's Bzip2Decoder poses a serious risk by allowing malicious input to trigger OOME and facilitate DoS attacks.

Technical Details of CVE-2021-37136

Here we delve into the technical specifics of CVE-2021-37136.

Vulnerability Description

The critical flaw in the Bzip2 decompression decoder function of Netty allows for unauthorized allocation sizes during decompression, leading to OOME and potential DoS exploitation.

Affected Systems and Versions

The Netty project's 'Netty' product versions preceding 4.1.68Final, including unspecified versions, are impacted by this vulnerability.

Exploitation Mechanism

By exploiting the absence of size restrictions, threat actors can use malicious input to manipulate decompression allocation sizes, causing OOME and enabling DoS attacks.

Mitigation and Prevention

In this section, we explore the steps to mitigate and prevent exploits from CVE-2021-37136.

Immediate Steps to Take

Update Netty to version 4.1.68Final or higher to address the vulnerability.
Implement network segmentation to minimize exposure to potential attackers.

Long-Term Security Practices

Conduct regular security audits and penetration testing to identify and address vulnerabilities proactively.
Educate developers on secure coding practices to prevent similar exploits in the future.

Patching and Updates

Stay informed about security updates from Netty and promptly apply patches to ensure protection against known vulnerabilities.