CVE-2025-46703 in BlueSpice
Summary
by MITRE • 09/19/2025
Improper Encoding or Escaping of Output vulnerability in Hallo Welt! GmbH BlueSpice (Extension:AtMentions) allows Cross-Site Scripting (XSS). This issue affects BlueSpice: from 5 through 5.1.1.
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Analysis
by VulDB Data Team • 09/23/2025
The vulnerability identified as CVE-2025-46703 represents a critical improper encoding or escaping of output flaw within the BlueSpice MediaWiki extension named AtMentions developed by Hallo Welt! GmbH. This specific weakness manifests as a cross-site scripting vulnerability that can be exploited by malicious actors to inject and execute arbitrary JavaScript code within the context of a victim's browser. The affected software versions span from BlueSpice 5.0.0 through 5.1.1, indicating a significant release range where this security gap exists and could potentially compromise user sessions and data integrity.
The technical root cause of this vulnerability stems from inadequate sanitization of user-provided input within the AtMentions extension functionality. When users interact with the mention system that allows tagging other users in wiki content, the extension fails to properly encode or escape special characters in the output rendering process. This insufficient output encoding creates an opening for attackers to inject malicious scripts that can execute in the browser context of other users who view the affected content. The vulnerability directly maps to CWE-79 which defines Cross-Site Scripting as a weakness where untrusted data is incorporated into web page content without proper validation or encoding, making it one of the most prevalent and dangerous web application security flaws.
The operational impact of this vulnerability extends beyond simple script execution as it can enable sophisticated attack vectors including session hijacking, credential theft, and data exfiltration. An attacker who successfully exploits this vulnerability could potentially impersonate legitimate users, access sensitive wiki content, modify pages, or even escalate privileges within the wiki environment. The attack surface is particularly concerning given that wiki platforms often contain sensitive organizational information, internal documentation, and collaborative workspaces where users may have elevated access rights. This vulnerability essentially transforms the wiki platform into a potential attack vector for broader network compromise, especially in enterprise environments where wiki systems serve as central collaboration hubs.
Mitigation strategies for this vulnerability should prioritize immediate patching of affected BlueSpice versions to the latest releases where the encoding issues have been resolved. Organizations should implement comprehensive input validation and output encoding mechanisms throughout their wiki platforms to prevent similar issues from occurring in other extensions or custom code. The implementation of Content Security Policy headers can provide additional protection layers against XSS attacks by restricting script execution from unauthorized sources. Security teams should conduct thorough penetration testing and code reviews of all wiki extensions to identify potential encoding gaps and ensure proper sanitization of user inputs. This vulnerability also underscores the importance of maintaining up-to-date security practices and regularly auditing third-party extensions for known security flaws, as highlighted in the ATT&CK framework's approach to web application security threats and the necessity of defensive measures against persistent XSS vulnerabilities.