CVE-2021-30129 : Exploit Details and Defense Strategies

A vulnerability in sshd-core of Apache Mina SSHD allows an attacker to overflow the server causing an OutOfMemory error. This article provides insights into CVE-2021-30129, its impact, technical details, and mitigation strategies.

Understanding CVE-2021-30129

CVE-2021-30129 is a Denial of Service (DoS) and Out-Of-Memory (OOM) leak vulnerability in Apache Mina SSHD Server.

What is CVE-2021-30129?

CVE-2021-30129 is a security vulnerability in the sshd-core of Apache Mina SSHD that permits an attacker to trigger an OutOfMemory error on the server, affecting the SFTP and port forwarding functionalities.

The Impact of CVE-2021-30129

The exploitation of CVE-2021-30129 can lead to resource exhaustion, causing a DoS condition on the affected Apache Mina SSHD server. This vulnerability affects version 2.0.0 and later, with a fix implemented in version 2.7.0.

Technical Details of CVE-2021-30129

CVE-2021-30129 Summary:

Vulnerability Description: The vulnerability in Apache Mina SSHD allows for server overflow and OutOfMemory error.
Affected Systems and Versions: Apache Mina SSHD version 2.0.0 and later are impacted, with Apache Mina SSHD 2.7.0 being the fix version.
Exploitation Mechanism: Attackers can trigger the vulnerability to exhaust server resources and induce a DoS condition.

Mitigation and Prevention

Implement the following measures to safeguard your systems against CVE-2021-30129:

Immediate Steps to Take

Upgrade to Apache Mina SSHD version 2.7.0 or later to mitigate the vulnerability.
Monitor server resources for any unusual spikes in memory usage.

Long-Term Security Practices

Regularly apply security patches and updates to ensure system resilience against known vulnerabilities.
Follow security best practices such as network segmentation and access control policies.

Patching and Updates

Stay informed about security advisories and promptly apply patches released by Apache Software Foundation to address security vulnerabilities.