CVE-2021-39225 : What You Need to Know
Learn about the CVE-2021-39225 vulnerability in Nextcloud's Deck API that allows authenticated users to access Deck cards of other users. Upgrade to secure versions and follow mitigation steps.
Nextcloud is an open-source, self-hosted productivity platform. A missing permission check in Nextcloud Deck before versions 1.2.9, 1.4.5, and 1.5.3 allows authenticated users to access another user's Deck cards. Upgrading to Nextcloud Deck App versions 1.2.9, 1.4.5, or 1.5.3 is recommended as there are no known workarounds.
Understanding CVE-2021-39225
This section provides insights into the nature and impact of the vulnerability.
What is CVE-2021-39225?
CVE-2021-39225 is a vulnerability in Nextcloud's Deck API that could enable authenticated users to access Deck cards of other users due to a missing permission check.
The Impact of CVE-2021-39225
The vulnerability has a CVSS base score of 8.1 (High severity).
- Attack Vector: Network
- Attack Complexity: Low
- Privileges Required: Low
- User Interaction: None
- Confidentiality Impact: High
- Integrity Impact: High
- Availability Impact: None
Technical Details of CVE-2021-39225
This section delves into the technical aspects of the vulnerability.
Vulnerability Description
The vulnerability arises from a missing permission check in Nextcloud Deck versions 1.2.9, 1.4.5, and 1.5.3, allowing unauthorized access to Deck cards.
Affected Systems and Versions
The following versions of Nextcloud's Deck are affected:
- Versions less than 1.2.9
- Versions greater than or equal to 1.4.0 and less than 1.4.5
- Versions greater than or equal to 1.5.0 and less than 1.5.3
Exploitation Mechanism
Attackers can exploit this vulnerability through authenticated access to Deck cards of other users without proper permission checks.
Mitigation and Prevention
Protecting systems from CVE-2021-39225 requires immediate actions and long-term security practices.
Immediate Steps to Take
- Upgrade Nextcloud Deck App to version 1.2.9, 1.4.5, or 1.5.3
Long-Term Security Practices
- Regularly update software to the latest versions
- Implement proper user permission checks to prevent unauthorized access
Patching and Updates
Stay informed about security advisories and apply patches promptly to address known vulnerabilities.