CVE-2023-28848 : Security Advisory and Response

This CVE-2023-28848 impacts the CSRF protection on user_oidc login in Nextcloud, an open-source collaboration platform. The vulnerability allowed attackers to bypass state protection by copying the expected state token from the first request to their second request. Users are recommended to upgrade user_oidc to version 1.3.0 to mitigate this issue.

Understanding CVE-2023-28848

This section provides detailed information on the vulnerability and its impact, along with technical details and mitigation strategies.

What is CVE-2023-28848?

CVE-2023-28848 is a Cross-Site Request Forgery (CSRF) vulnerability in the user_oidc component of Nextcloud versions 1.0.0 to 1.3.0. Attackers could exploit this vulnerability to bypass state protection mechanisms, potentially leading to unauthorized actions being performed on behalf of authenticated users.

The Impact of CVE-2023-28848

Due to this vulnerability, attackers could manipulate the state token to impersonate users and perform unauthorized actions within the Nextcloud platform. This could lead to data theft, unauthorized access, and other security breaches.

Technical Details of CVE-2023-28848

The following technical details outline the vulnerability, affected systems, and how the exploitation could be carried out.

Vulnerability Description

The vulnerability in user_oidc allowed attackers to copy the expected state token from one request to another, bypassing security measures and potentially gaining unauthorized access to user accounts and data.

Affected Systems and Versions

Nextcloud versions between 1.0.0 and 1.3.0 are affected by this vulnerability in the user_oidc component. Users using these versions are at risk of exploitation and should update to version 1.3.0 to patch the issue.

Exploitation Mechanism

Attackers with high privileges could exploit this vulnerability by manipulating the state token in the user_oidc login process, allowing them to perform unauthorized actions within the platform.

Mitigation and Prevention

To safeguard systems from CVE-2023-28848 and similar vulnerabilities, it is essential to implement immediate steps and long-term security practices.

Immediate Steps to Take

Users are advised to upgrade user_oidc to version 1.3.0 as soon as possible to receive the necessary patch for this CSRF vulnerability. Additionally, users should monitor their Nextcloud instances for any suspicious activities.

Long-Term Security Practices

Implementing strong access controls, regular security updates, and security audits can help prevent CSRF attacks and other security threats. Training users on secure authentication practices is also crucial in maintaining overall system security.

Patching and Updates

Regularly updating Nextcloud instances, plugins, and dependencies to the latest secure versions can help mitigate the risk of CSRF vulnerabilities and other security issues. Stay informed about security advisories and apply patches promptly to ensure a secure environment.