CVE-2023-28846 Explained : Impact and Mitigation

This CVE record pertains to a Denial of Service vulnerability in the

unpoly-rails

gem, impacting Rails applications using Unpoly's server protocol. The vulnerability, identified as CWE-400: Uncontrolled Resource Consumption, allows attackers to trigger a DoS attack by exploiting a specific behavior in the gem that results in generating excessively large response headers.

Understanding CVE-2023-28846

This section delves into the details of the CVE-2023-28846 vulnerability affecting the

unpoly-rails

gem used in Rails applications.

What is CVE-2023-28846?

The CVE-2023-28846 vulnerability involves the

unpoly-rails

gem, a JavaScript framework for server-side web applications. Attackers can exploit this flaw to cause a Denial of Service (DoS) by crafting requests with abnormally long URLs. This can lead to generating response headers of excessive size, potentially affecting the functioning of load balancers used in the affected Rails applications.

The Impact of CVE-2023-28846

The impact of this vulnerability is rated as MEDIUM severity based on the CVSS v3.1 scoring system. With a base score of 5.9, the vulnerability has a high impact on availability, potentially causing disruption to the affected systems.

Technical Details of CVE-2023-28846

This section provides a technical overview of the CVE-2023-28846 vulnerability, including its description, affected systems and versions, as well as the exploitation mechanism.

Vulnerability Description

The vulnerability in

unpoly-rails

gem allows attackers to exploit load balancers using passive health checks by sending requests with unusually long URLs. This triggers the generation of oversized response headers, potentially leading to service disruption.

Affected Systems and Versions

The

unpoly-rails

gem versions prior to 2.7.2.2 are susceptible to this vulnerability. Systems utilizing these versions are at risk of being impacted by the DoS attack vector.

Exploitation Mechanism

Attackers can exploit this vulnerability by submitting HTTP requests with extended URLs comprising lengthy paths or query strings. This triggers the creation of exceptionally large response headers, posing a threat to the stability of load balancers processing these requests.

Mitigation and Prevention

In addressing CVE-2023-28846, it is essential to implement immediate steps to mitigate the risk and prevent potential exploitation.

Immediate Steps to Take

To mitigate the impact of CVE-2023-28846, users are advised to upgrade to version 2.7.2.2 of the

unpoly-rails

gem. Alternatively, implementing active health checks on load balancers, adjusting response header size limits, and addressing redundant response headers can help mitigate the vulnerability.

Long-Term Security Practices

In the long term, maintaining up-to-date software versions, monitoring security advisories, and adopting secure coding practices can help enhance the overall security posture of web applications using the

unpoly-rails

gem.

Patching and Updates

Users are encouraged to promptly apply the patched version 2.7.2.2 of the

unpoly-rails

gem to remediate the vulnerability. Regularly checking for security updates and maintaining awareness of emerging threats is crucial for ensuring the ongoing protection of vulnerable systems.