CVE-2025-62749 is a DOM-based Cross-site Scripting (XSS) vulnerability identified in the Bainternet User Specific Content product, affecting versions up to 1.0.6. This vulnerability stems from improper neutralization of user input during the generation of web pages, specifically within the Document Object Model (DOM), which allows malicious scripts to be injected and executed in the context of the victim's browser. Unlike traditional reflected or stored XSS, DOM-based XSS occurs entirely on the client side, making detection and mitigation more challenging. The vulnerability requires an attacker to have low privileges (PR:L) and some user interaction (UI:R), such as tricking a user into clicking a crafted link or visiting a malicious page. The CVSS 3.1 vector indicates network attack vector (AV:N), low attack complexity (AC:L), and scope change (S:C), meaning the vulnerability can affect resources beyond the initially compromised component. The impact includes partial loss of confidentiality, integrity, and availability, such as session hijacking, unauthorized actions on behalf of users, and potential defacement or disruption of services. No patches are currently listed, and no known exploits have been reported in the wild, but the vulnerability is publicly disclosed and should be considered a credible risk. The CWE-79 classification confirms the issue is due to improper input sanitization, a common and critical web security flaw. Organizations using Bainternet User Specific Content should monitor for updates and prepare to implement mitigations to prevent exploitation.

For European organizations, this vulnerability poses a significant risk to web applications that utilize Bainternet User Specific Content, especially those handling sensitive user data or providing critical services. Successful exploitation can lead to session hijacking, allowing attackers to impersonate legitimate users and access confidential information. Integrity of data can be compromised through unauthorized actions performed via injected scripts, potentially leading to fraudulent transactions or data manipulation. Availability may also be affected if attackers use the vulnerability to execute denial-of-service attacks or disrupt normal application behavior. Given the medium CVSS score and the requirement for user interaction, the threat is moderate but can escalate if combined with social engineering or other attack vectors. Organizations in sectors such as finance, healthcare, and government are particularly at risk due to the sensitivity of their data and regulatory requirements under GDPR. Additionally, the scope change in the CVSS vector suggests that exploitation could impact multiple components or users beyond the initial target, increasing the potential damage. The lack of known exploits in the wild currently reduces immediate risk but does not eliminate the need for proactive measures.

1. Monitor Bainternet vendor communications closely for official patches or updates addressing CVE-2025-62749 and apply them promptly once available. 2. Implement strict input validation on all user-supplied data, ensuring that inputs are sanitized and validated both on client and server sides to prevent malicious script injection. 3. Employ robust output encoding techniques, especially when inserting user input into the DOM, to neutralize potentially harmful characters. 4. Deploy Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts and reduce the impact of any successful injection. 5. Conduct regular security code reviews and penetration testing focused on client-side scripting and DOM manipulation to identify and remediate similar vulnerabilities. 6. Educate users and staff about phishing and social engineering tactics that could facilitate exploitation through user interaction. 7. Utilize web application firewalls (WAFs) with rules tailored to detect and block XSS attack patterns targeting the affected product. 8. Isolate critical web application components and limit privileges to reduce the scope of potential exploitation. 9. Maintain comprehensive logging and monitoring to detect suspicious activities indicative of attempted or successful exploitation. 10. Consider implementing multi-factor authentication to mitigate the impact of session hijacking.