CVE-2021-23664 : Exploit Details and Defense Strategies

Server-side Request Forgery (SSRF) vulnerability has been discovered in the package @isomorphic-git/cors-proxy before version 2.7.1. This CVE was made public on January 21, 2022, and has a base score of 8.6 (High Severity) with a CVSSv3.1 score of 8.1.

Understanding CVE-2021-23664

This section will provide insights into the vulnerability, its impact, technical details, and mitigation strategies.

What is CVE-2021-23664?

The CVE-2021-23664 vulnerability involves missing sanitization and validation of the redirection action in middleware.js in the @isomorphic-git/cors-proxy package before version 2.7.1. This can lead to SSRF attacks.

The Impact of CVE-2021-23664

With a CVSSv3.1 base score of 8.6 (High Severity), this vulnerability can result in Server-Side Request Forgery (SSRF) attacks, potentially exposing sensitive data and impacting the confidentiality of the system.

Technical Details of CVE-2021-23664

In this section, we will delve into the vulnerability description, affected systems and versions, as well as the exploitation mechanism.

Vulnerability Description

The SSRF vulnerability arises due to a lack of proper sanitization and validation of the redirection action in middleware.js in versions prior to 2.7.1 of the @isomorphic-git/cors-proxy package.

Affected Systems and Versions

The vulnerability affects versions of @isomorphic-git/cors-proxy that are less than 2.7.1, with a custom version type.

Exploitation Mechanism

Attackers can exploit this vulnerability to perform SSRF attacks by manipulating the redirection action, potentially accessing internal resources or conducting further attacks.

Mitigation and Prevention

To address CVE-2021-23664, it is crucial to take immediate steps, implement long-term security practices, and apply relevant patches and updates.

Immediate Steps to Take

Developers and administrators should update the @isomorphic-git/cors-proxy package to version 2.7.1 or above to mitigate the SSRF vulnerability. Additionally, network-level protections can be implemented to block malicious requests.

Long-Term Security Practices

Incorporate secure coding practices, perform regular security assessments, monitor network traffic for suspicious activities, and educate users about the risks associated with SSRF vulnerabilities.

Patching and Updates

Stay informed about security advisories and updates related to @isomorphic-git/cors-proxy to ensure timely application of patches and fixes.