CVE-2021-22904 : Exploit Details and Defense Strategies

The actionpack ruby gem before versions 6.1.3.2, 6.0.3.7, 5.2.4.6, 5.2.6 is impacted by a denial of service vulnerability in the Token Authentication logic in Action Controller. This vulnerability arises due to a too permissive regular expression in code that uses

authenticate_or_request_with_http_token

or

authenticate_with_http_token

for request authentication.

Understanding CVE-2021-22904

This section will cover details about the CVE-2021-22904 vulnerability.

What is CVE-2021-22904?

The CVE-2021-22904 vulnerability affects the actionpack ruby gem versions before 6.1.3.2, 6.0.3.7, 5.2.4.6, 5.2.6, leading to a denial of service risk in the Token Authentication logic in Action Controller.

The Impact of CVE-2021-22904

The vulnerability can be exploited to launch denial of service attacks, potentially disrupting services relying on the affected versions of the actionpack ruby gem.

Technical Details of CVE-2021-22904

This section will provide technical insights into CVE-2021-22904.

Vulnerability Description

The vulnerability in the Token Authentication logic allows attackers to abuse the permissive regular expression, leading to denial of service risks.

Affected Systems and Versions

The actionpack ruby gem versions prior to 6.1.3.2, 6.0.3.7, 5.2.4.6, 5.2.6 are impacted by this vulnerability, necessitating immediate attention.

Exploitation Mechanism

Attackers can exploit this vulnerability by manipulating the Token Authentication logic using specific requests to trigger a denial of service.

Mitigation and Prevention

In this section, we will discuss mitigation strategies for CVE-2021-22904.

Immediate Steps to Take

Users are advised to update to the fixed versions, namely 6.1.3.2, 6.0.3.7, 5.2.4.6, or 5.2.6, to remediate the vulnerability.

Long-Term Security Practices

Adopting strong input validation and regular security updates can help prevent similar vulnerabilities in the future.

Patching and Updates

Regularly applying patches and staying updated with the latest security releases from the actionpack ruby gem can enhance the overall security posture of applications.