CVE-2025-12460 is a Cross-site Scripting (XSS) vulnerability classified under CWE-79, discovered in Afterlogic Aurora webmail versions 9.8.3 and earlier. The vulnerability arises from improper neutralization of input during web page generation, specifically when rendering HTML email content. An attacker can craft an email containing malicious JavaScript embedded within an img HTML tag. When a user opens or previews this email in the vulnerable webmail client, the JavaScript executes within the user's browser context. This execution can lead to unauthorized access to sensitive user data, session tokens, or enable further malicious actions such as redirecting the user or stealing credentials. The vulnerability is remotely exploitable without authentication, but requires the user to interact with the malicious email (e.g., open or preview it). The CVSS 4.0 base score is 5.3 (medium severity), reflecting the network attack vector, low complexity, no privileges required, but requiring user interaction and having limited impact on confidentiality and integrity. No public exploits are currently known, and no official patches have been linked yet. The vulnerability highlights the risks inherent in rendering untrusted HTML content without proper sanitization in webmail clients.

For European organizations, this vulnerability poses a risk to the confidentiality and integrity of user data accessed through Afterlogic Aurora webmail. Successful exploitation could lead to unauthorized disclosure of sensitive emails, session hijacking, or further compromise of user accounts. This is particularly concerning for sectors handling sensitive or regulated data such as finance, healthcare, government, and critical infrastructure. The medium severity indicates moderate risk, but the ease of exploitation (no authentication needed) and the widespread use of webmail clients increase the potential attack surface. Organizations relying on Afterlogic Aurora for internal or external email services could face targeted phishing campaigns leveraging this vulnerability. Additionally, compromised user accounts could be used as a foothold for lateral movement within networks. The impact on availability is minimal, but the breach of confidentiality and integrity can have significant operational and reputational consequences under European data protection regulations like GDPR.

To mitigate this vulnerability, European organizations should: 1) Immediately implement strict email content filtering to block or sanitize incoming emails containing suspicious HTML or JavaScript, especially those with img tags containing scripts. 2) Disable automatic HTML rendering or preview features in Afterlogic Aurora webmail until a vendor patch is available. 3) Educate users about the risks of opening unexpected or suspicious emails, emphasizing caution with HTML content. 4) Monitor webmail logs for unusual activity indicative of exploitation attempts. 5) Apply vendor patches promptly once released; if no patch is available, consider temporary workarounds such as using alternative email clients or disabling vulnerable features. 6) Employ Content Security Policy (CSP) headers if supported by the webmail platform to restrict script execution. 7) Conduct regular security assessments and penetration testing focused on webmail systems to detect similar vulnerabilities. These steps go beyond generic advice by focusing on email content filtering, user awareness, and configuration changes specific to Afterlogic Aurora.