CVE-2021-33582 : Vulnerability Insights and Analysis

Cyrus IMAP before version 3.4.2 has a vulnerability that allows remote attackers to trigger a denial of service. This can lead to a multiple-minute daemon hang due to mishandling of input during hash-table interaction. The issue is addressed in versions 3.4.2, 3.2.8, and 3.0.16.

Understanding CVE-2021-33582

This section will delve into the details of the vulnerability and its potential impact.

What is CVE-2021-33582?

CVE-2021-33582 is a vulnerability in Cyrus IMAP versions before 3.4.2 that enables remote attackers to create a denial of service situation by causing a prolonged daemon hang.

The Impact of CVE-2021-33582

The impact of this vulnerability is the disruption of IMAP service availability, resulting in a significant delay in processing client requests.

Technical Details of CVE-2021-33582

In this section, we will explore the technical aspects of the CVE for a better understanding of the issue.

Vulnerability Description

The vulnerability arises from improper input handling during hash-table interaction in Cyrus IMAP, leading to a slowdown in strcmp due to numerous insertions in a single bucket.

Affected Systems and Versions

Cyrus IMAP versions before 3.4.2 are affected by this vulnerability, while versions 3.4.2, 3.2.8, and 3.0.16 contain the necessary fixes.

Exploitation Mechanism

Remote attackers can exploit this vulnerability by sending specially crafted input to the affected Cyrus IMAP server, triggering the denial of service condition.

Mitigation and Prevention

To address and prevent the exploitation of CVE-2021-33582, consider the following steps:

Immediate Steps to Take

Update Cyrus IMAP to version 3.4.2, 3.2.8, or 3.0.16 to mitigate the vulnerability.
Monitor for any unusual system behavior or performance issues that may indicate a potential attack.

Long-Term Security Practices

Regularly update software components to ensure the latest security patches are applied.
Implement network segmentation and access controls to restrict unauthorized access to critical systems.

Patching and Updates

Refer to official sources like Cyrus IMAP release notes and vendor advisories for patching guidance and updates.