CVE-2025-29690 is a cross-site scripting (XSS) vulnerability identified in the OA System, affecting versions prior to 2025.01.01. The vulnerability arises from insufficient input sanitization of the 'outtype' parameter in the /address/AddrController.java endpoint. An attacker can craft a malicious payload injected into this parameter, which is then executed as arbitrary web scripts or HTML in the context of the victim's browser. This type of vulnerability falls under CWE-79, indicating improper neutralization of input during web page generation. The CVSS v3.1 base score is 6.1, reflecting a medium severity level. The vector indicates that the attack can be performed remotely over the network (AV:N), requires no privileges (PR:N), but does require user interaction (UI:R), and has a scope change (S:C) meaning the vulnerability affects resources beyond the vulnerable component. The impact affects confidentiality and integrity at a low level, with no impact on availability. No known exploits are currently reported in the wild, and no patches or vendor advisories are listed yet. The vulnerability could be leveraged to execute malicious scripts in users' browsers, potentially leading to session hijacking, theft of sensitive information, or unauthorized actions performed on behalf of the user within the OA System application context.

For European organizations using the OA System, this XSS vulnerability poses a risk primarily to the confidentiality and integrity of user data accessed through the affected web interface. Attackers exploiting this flaw could steal session cookies, enabling unauthorized access to user accounts, or manipulate displayed content to deceive users (phishing). This could lead to data breaches involving personal or corporate information, undermining trust and potentially violating GDPR requirements for data protection. Since the vulnerability requires user interaction, social engineering could be used to lure employees into clicking malicious links. The scope change indicates that the attack could affect other components or users beyond the initially targeted area, increasing the potential damage. Although availability is not impacted, the reputational damage and regulatory consequences could be significant. Organizations in sectors with high compliance demands, such as finance, healthcare, and government, may face increased scrutiny and penalties if exploited.

To mitigate this vulnerability, European organizations should first identify if they are using the OA System and confirm the version in use. Immediate steps include: 1) Applying any available patches or updates from the OA System vendor once released. 2) Implementing web application firewalls (WAFs) with rules to detect and block malicious payloads targeting the 'outtype' parameter. 3) Conducting input validation and output encoding on all user-supplied data, especially parameters that influence HTML or script generation, to neutralize potentially harmful content. 4) Educating users about the risks of clicking on suspicious links and employing email filtering to reduce phishing attempts. 5) Monitoring web logs for unusual requests targeting the vulnerable endpoint. 6) Employing Content Security Policy (CSP) headers to restrict execution of unauthorized scripts in browsers. 7) Reviewing and enhancing session management to limit the impact of stolen session tokens. These measures, combined with prompt patching, will reduce the risk of exploitation.