CVE-2025-48921 is a Cross-Site Request Forgery (CSRF) vulnerability identified in the Drupal Open Social platform, affecting versions from 0.0.0 before 12.3.14 and from 12.4.0 before 12.4.13. Open Social is a community engagement platform built on Drupal, widely used for creating online social communities, intranets, and collaboration portals. CSRF vulnerabilities allow an attacker to trick authenticated users into submitting unwanted actions on a web application where they are currently logged in, without their consent or knowledge. This can lead to unauthorized state-changing requests such as modifying user settings, posting content, or changing permissions. The vulnerability arises because the affected versions of Open Social do not adequately verify that requests originate from legitimate users or trusted sources, lacking proper anti-CSRF tokens or validation mechanisms. Although no known exploits are currently reported in the wild, the presence of this vulnerability poses a significant risk, especially in environments where users have elevated privileges or where sensitive operations can be triggered via web requests. The absence of a CVSS score indicates that the vulnerability has been recently published and not yet fully assessed, but the nature of CSRF flaws generally implies a moderate to high risk depending on context. Since Open Social is often deployed in organizational intranets and community portals, exploitation could lead to unauthorized actions performed on behalf of legitimate users, potentially compromising data integrity and user trust.

For European organizations, the impact of this CSRF vulnerability can be substantial. Many public sector institutions, universities, NGOs, and private enterprises in Europe use Drupal Open Social to manage internal and external community engagement platforms. Successful exploitation could allow attackers to perform unauthorized actions such as changing user roles, posting misleading or malicious content, or altering configuration settings, which could disrupt operations or damage reputations. Given the GDPR regulatory environment, unauthorized data manipulation or exposure resulting from such attacks could lead to compliance violations and significant fines. Additionally, if attackers leverage CSRF to escalate privileges or pivot to other parts of the network, this could lead to broader security breaches. The risk is heightened in organizations with large user bases and complex permission structures, where automated or targeted CSRF attacks could cause widespread disruption or data integrity issues.

To mitigate this vulnerability, European organizations using Drupal Open Social should immediately upgrade to the latest patched versions beyond 12.3.14 and 12.4.13 once available. In the interim, administrators should implement strict CSRF protections by ensuring that all state-changing requests require valid anti-CSRF tokens and that these tokens are verified server-side. Reviewing and tightening user permissions to follow the principle of least privilege can reduce the impact of potential exploitation. Organizations should also conduct thorough audits of their Open Social configurations and custom modules to ensure no additional CSRF weaknesses exist. Employing web application firewalls (WAFs) with rules to detect and block suspicious cross-site requests can provide an additional layer of defense. User education about phishing and social engineering risks can help reduce the likelihood of users being tricked into executing malicious requests. Finally, monitoring logs for unusual or unauthorized actions can enable early detection of exploitation attempts.