CVE-2025-28989 is a medium-severity vulnerability classified under CWE-79, which corresponds to Improper Neutralization of Input During Web Page Generation, commonly known as Cross-site Scripting (XSS). This vulnerability affects the 'Read More Login' product developed by arildur, specifically versions up to 2.0.3. The flaw allows for Stored XSS attacks, where malicious input is persistently stored by the application and later rendered in users' browsers without proper sanitization or encoding. This enables attackers to execute arbitrary JavaScript code within the context of the victim's browser session. The CVSS 3.1 base score is 5.9, reflecting a network attack vector (AV:N), low attack complexity (AC:L), but requiring high privileges (PR:H) and user interaction (UI:R). The scope is changed (S:C), indicating that the vulnerability affects resources beyond the initially vulnerable component. The impact affects confidentiality, integrity, and availability at a low level, as the attacker can potentially steal session tokens, manipulate displayed content, or perform actions on behalf of the user. No known exploits are currently reported in the wild, and no patches have been linked yet. The vulnerability was reserved in March 2025 and published in June 2025, indicating recent disclosure. Stored XSS vulnerabilities are particularly dangerous because they can affect multiple users and persist over time, increasing the attack surface and potential damage. The requirement for high privileges suggests that the attacker must have some level of authenticated access to inject the malicious payload, and user interaction is needed to trigger the exploit, which somewhat limits the ease of exploitation but does not eliminate risk, especially in environments with many users or administrators. The changed scope implies that the vulnerability could impact other components or users beyond the initial context, potentially leading to broader compromise within the affected system.

For European organizations using the 'Read More Login' product, this vulnerability poses a risk of session hijacking, unauthorized actions, and data leakage through malicious script execution in users' browsers. Given the stored nature of the XSS, attackers could embed persistent malicious scripts that affect multiple users, including administrators, thereby escalating the potential damage. This could lead to compromised user accounts, unauthorized access to sensitive information, and disruption of normal operations. The medium severity and requirement for high privileges mean that insider threats or compromised accounts could be leveraged to exploit this vulnerability. Organizations in sectors with stringent data protection regulations, such as finance, healthcare, and government, could face compliance issues and reputational damage if exploited. Additionally, the vulnerability could be used as a foothold for further attacks within the network, especially in complex European enterprise environments where single sign-on and integrated web applications are common. The lack of known exploits in the wild provides a window for proactive mitigation, but the recent disclosure means that attackers may develop exploits soon, increasing urgency for remediation.

European organizations should implement several specific measures to mitigate this vulnerability effectively: 1) Immediate review and restriction of user privileges to minimize the number of users with high-level access capable of injecting malicious input. 2) Employ rigorous input validation and output encoding on all user-supplied data within the 'Read More Login' application, focusing on contexts where data is rendered in HTML, JavaScript, or attributes. 3) Monitor and audit logs for unusual input patterns or attempts to inject scripts, especially from privileged users. 4) Implement Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in browsers, reducing the impact of potential XSS payloads. 5) Isolate the 'Read More Login' application within a secure network segment and limit its integration with critical systems to contain potential exploitation. 6) Engage with the vendor or community to obtain patches or updates as soon as they become available, and apply them promptly. 7) Conduct user awareness training emphasizing the risks of clicking on suspicious links or interacting with unexpected prompts, as user interaction is required for exploitation. 8) Utilize web application firewalls (WAF) with custom rules to detect and block common XSS attack patterns targeting this application. These targeted actions go beyond generic advice by focusing on privilege management, monitoring, and layered defenses tailored to the specifics of this vulnerability and product.