CVE-2021-38621 Explained : Impact and Mitigation

This article provides an overview of CVE-2021-38621, focusing on its impact, technical details, and mitigation strategies.

Understanding CVE-2021-38621

CVE-2021-38621 is a vulnerability in the remove API of netless Agora Flat Server before 2021-07-30, leading to mishandling of file ownership.

What is CVE-2021-38621?

The remove API in v1/controller/cloudStorage/alibabaCloud/remove/index.ts in netless Agora Flat Server fails to properly manage file ownership, which could result in unauthorized access to files.

The Impact of CVE-2021-38621

This vulnerability could allow attackers to gain unauthorized access to sensitive files stored on the affected Agora Flat Server instances, potentially leading to data breaches or unauthorized modifications.

Technical Details of CVE-2021-38621

The technical details of CVE-2021-38621 include the vulnerability description, affected systems and versions, and the exploitation mechanism.

Vulnerability Description

CVE-2021-38621 arises from the improper handling of file ownership within the remove API of netless Agora Flat Server, enabling attackers to manipulate files.

Affected Systems and Versions

All versions of netless Agora Flat Server released before 2021-07-30 are impacted by CVE-2021-38621.

Exploitation Mechanism

Attackers can exploit this vulnerability by sending specially crafted requests to the remove API, manipulating file ownership to gain unauthorized access.

Mitigation and Prevention

To mitigate the risks associated with CVE-2021-38621, immediate steps should be taken along with the implementation of long-term security practices and timely patching.

Immediate Steps to Take

Update netless Agora Flat Server to a version released after 2021-07-30 to eliminate the vulnerability.
Monitor system logs for any suspicious file access or manipulation activities.

Long-Term Security Practices

Enforce the principle of least privilege to restrict file access based on user roles.
Regularly audit file ownership permissions on the server to detect unauthorized changes.

Patching and Updates

Stay informed about security updates from netless Agora and promptly apply patches to secure your system against known vulnerabilities.