CVE-2021-23435 : What You Need to Know

This CVE-2021-23435 article provides an overview of an Open Redirect vulnerability in the Clearance package before version 2.5.0.

Understanding CVE-2021-23435

CVE-2021-23435 is a vulnerability that affects the Clearance package versions prior to 2.5.0. The security issue arises when users can manipulate the session[:return_to] value, leading to an open redirect vulnerability.

What is CVE-2021-23435?

CVE-2021-23435 is an Open Redirect vulnerability that exists in the Clearance package before version 2.5.0. It occurs when users can modify the return_to value in the session to redirect to an external domain.

The Impact of CVE-2021-23435

The vulnerability allows attackers to craft a malicious return_to URL with multiple leading slashes, leading users to unintentionally access an external domain, potentially exposing them to phishing attacks or malicious content.

Technical Details of CVE-2021-23435

The technical details of CVE-2021-23435 are as follows:

Vulnerability Description

The vulnerability in Clearance package versions prior to 2.5.0 allows for open redirect attacks by manipulating the return_to value in the session.

Affected Systems and Versions

Versions of the Clearance package that are less than 2.5.0 are affected by this vulnerability.

Exploitation Mechanism

Attackers can exploit this vulnerability by setting a crafted return_to value with multiple leading slashes, leading to a redirection to an external domain.

Mitigation and Prevention

To mitigate the risks associated with CVE-2021-23435, consider the following steps:

Immediate Steps to Take

Update the Clearance package to version 2.5.0 or above to address the vulnerability.
Avoid clicking on suspicious or unknown links that may contain manipulated return_to values.

Long-Term Security Practices

Regularly monitor and update software dependencies to patch known vulnerabilities.
Educate users and developers about the risks of open redirect attacks and best security practices.

Patching and Updates

Stay informed about security updates and patches released by the Clearance package maintainers to address known vulnerabilities.