CVE-2022-3893 is a Cross-site Scripting (XSS) vulnerability identified in the BlueSpiceCustomMenu extension of the BlueSpice software, developed by Hallo Welt! GmbH. BlueSpice is a wiki software platform often used for knowledge management and collaboration within organizations. The vulnerability specifically affects version 4 of BlueSpice. The flaw allows a user with administrative privileges to inject arbitrary HTML code into the custom menu navigation of the application. This injection occurs because the extension does not properly sanitize or encode user-supplied input before rendering it in the menu interface. The vulnerability is classified under CWE-79, indicating improper neutralization of input during web page generation. The CVSS v3.1 base score is 2.3, reflecting a low severity level. The vector string (AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N) indicates that the attack requires local access (AV:L), low attack complexity (AC:L), high privileges (PR:H), no user interaction (UI:N), unchanged scope (S:U), and impacts confidentiality only to a limited extent (C:L), with no impact on integrity or availability. There are no known exploits in the wild, and no official patches have been linked or published as of the date provided. The vulnerability is primarily a risk of HTML injection that could lead to limited information disclosure or UI manipulation within the context of an admin user session. Since the attacker must already have admin privileges, the attack surface is restricted to trusted users who have access to the BlueSpice administrative interface. This reduces the likelihood of widespread exploitation but still poses a risk within organizations where admin credentials could be compromised or misused.

For European organizations using BlueSpice version 4, this vulnerability presents a limited but noteworthy risk. Since exploitation requires administrative privileges, the threat is primarily insider or credential compromise related. Successful exploitation could allow an attacker to inject malicious HTML into the navigation menu, potentially enabling phishing attempts within the application, session hijacking, or disclosure of sensitive information visible only to admins. While the direct impact on confidentiality is low, the ability to manipulate the UI could facilitate further attacks or social engineering within the trusted environment. Organizations with sensitive internal knowledge bases or collaborative platforms relying on BlueSpice may face reputational risks or operational disruptions if attackers leverage this vulnerability to mislead administrators or extract information. However, the lack of impact on integrity and availability means that core data and system operations are unlikely to be directly compromised by this vulnerability alone. The risk is compounded in environments where administrative access controls are weak or where multiple administrators share credentials. European organizations with strict data protection regulations (e.g., GDPR) should consider the potential for indirect data exposure or misuse as a compliance concern, even if the technical severity is low.

1. Restrict administrative access strictly: Ensure that only trusted personnel have admin privileges in BlueSpice, and enforce strong authentication mechanisms such as multi-factor authentication (MFA) to reduce the risk of credential compromise. 2. Implement input validation and output encoding: Although no official patch is linked, administrators should review and sanitize any custom menu inputs manually to prevent injection of malicious HTML. Consider disabling or limiting the use of the BlueSpiceCustomMenu extension until a patch is available. 3. Monitor admin activity logs: Enable detailed logging of administrative actions within BlueSpice to detect any unusual modifications to the custom menu or other configuration changes that could indicate exploitation attempts. 4. Conduct regular security audits: Periodically review user permissions and audit the BlueSpice environment for unauthorized changes or suspicious behavior. 5. Network segmentation: Limit access to the BlueSpice administrative interface to trusted internal networks or VPNs to reduce exposure to potential attackers. 6. Stay updated: Monitor Hallo Welt! GmbH’s official channels for any forthcoming patches or security advisories addressing this vulnerability and apply updates promptly. 7. Educate administrators: Train BlueSpice admins on the risks of XSS and safe handling of custom menu content to avoid inadvertent injection of unsafe code.