CVE-2021-35516 Explained : Impact and Mitigation

Apache Commons Compress 1.6 to 1.20 denial of service vulnerability allows attackers to trigger an out-of-memory error by exploiting specially crafted 7Z archives. This could lead to a denial of service attack on services using the Compress' sevenz package.

Understanding CVE-2021-35516

This section will delve into the details of the CVE-2021-35516 vulnerability.

What is CVE-2021-35516?

CVE-2021-35516 refers to the denial of service vulnerability in Apache Commons Compress versions 1.6 to 1.20. Attackers can exploit this issue by causing Compress to allocate excessive memory through specially crafted 7Z archives.

The Impact of CVE-2021-35516

The exploitation of CVE-2021-35516 can result in an out-of-memory error even for small input sizes. This vulnerability poses a threat as it can be used to perform denial of service attacks on systems utilizing Compress' sevenz package.

Technical Details of CVE-2021-35516

This section will provide a deeper insight into the technical aspects of CVE-2021-35516.

Vulnerability Description

When processing malicious 7Z archives, Apache Commons Compress can allocate significant memory, causing out-of-memory errors, making it susceptible to DoS attacks.

Affected Systems and Versions

Apache Commons Compress versions 1.6 to 1.20 are affected by this vulnerability.

Exploitation Mechanism

Attackers can exploit this vulnerability by crafting specially designed 7Z archives to trigger out-of-memory errors.

Mitigation and Prevention

Understanding how to address and prevent CVE-2021-35516 is crucial for maintaining system security.

Immediate Steps to Take

Users are advised to upgrade to Apache Commons Compress version 1.21 or later to mitigate the vulnerability. Additional measures include disabling the recovery code introduced in version 1.19 and controlling memory usage for SevenZFile.

Long-Term Security Practices

Implementing secure coding practices and adopting regular security audits can help prevent and detect similar vulnerabilities in the future.

Patching and Updates

It is essential to stay updated with the latest security patches and advisories released by Apache Commons to address vulnerabilities like CVE-2021-35516 effectively.