CVE-2021-3915 : What You Need to Know

bookstack is vulnerable to Unrestricted Upload of File with Dangerous Type

Understanding CVE-2021-3915

This CVE highlights a vulnerability in the bookstackapp/bookstack container related to the unrestricted upload of a file with a dangerous type.

What is CVE-2021-3915?

The vulnerability in bookstackapp/bookstack allows attackers to upload files with dangerous types without proper validation or restrictions, potentially leading to serious security implications.

The Impact of CVE-2021-3915

With a CVSS base score of 7.6 (High Severity), this vulnerability can result in high confidentiality impact, low integrity impact, and high availability impact. Attackers with low privileges can exploit this vulnerability over the network, requiring user interaction.

Technical Details of CVE-2021-3915

This section delves into the specific technical aspects of CVE-2021-3915.

Vulnerability Description

bookstackapp/bookstack is vulnerable to the unrestricted upload of a file with a dangerous type, allowing attackers to bypass security measures and potentially execute malicious payloads.

Affected Systems and Versions

The vulnerability affects versions of bookstackapp/bookstack prior to version 21.10.3, with custom versions potentially also being impacted.

Exploitation Mechanism

Attackers can exploit this vulnerability by uploading files with dangerous types, which may contain malicious content that can harm the system or compromise sensitive data.

Mitigation and Prevention

In order to mitigate the risks associated with CVE-2021-3915, immediate actions as well as long-term security practices are essential.

Immediate Steps to Take

Users and administrators should update bookstackapp/bookstack to version 21.10.3 or later to prevent exploitation of this vulnerability. Additionally, file upload functionalities should be reviewed and validated to ensure that only safe file types are permitted.

Long-Term Security Practices

Implementing strict file upload validations, conducting regular security assessments, and educating users about safe file handling practices can help prevent similar vulnerabilities in the future.

Patching and Updates

Regularly check for security updates and patches released by bookstackapp to address known vulnerabilities and improve the overall security posture of the system.