CVE-2025-29231 is a stored cross-site scripting (XSS) vulnerability identified in the page_save component of the Linksys E5600 router firmware version 1.1.0.26. The vulnerability arises because the hostname and domainName parameters are not properly sanitized before being stored and subsequently rendered in the router's web management interface. An attacker can craft a malicious payload and inject it into these parameters, which, when viewed by an administrator or user with access to the router's web interface, executes arbitrary JavaScript or HTML code. This type of vulnerability is classified under CWE-79 (Improper Neutralization of Input During Web Page Generation). The CVSS v3.1 base score is 6.1, indicating a medium severity level, with the vector AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N. This means the attack can be performed remotely over the network without privileges, requires user interaction (such as an admin visiting the affected page), and affects confidentiality and integrity with a scope change (the vulnerability affects components beyond the initially vulnerable component). There are no known public exploits or patches available at the time of publication. The vulnerability could allow attackers to steal sensitive information, hijack sessions, or perform unauthorized actions within the router's management interface, potentially leading to further network compromise. The lack of authentication requirements for the attack vector and the router's common use in enterprise and home networks make this a notable risk.

For European organizations, the exploitation of this vulnerability could lead to unauthorized execution of scripts within the router's management interface, potentially exposing sensitive configuration data such as network settings, credentials, or session tokens. This could facilitate further attacks like network reconnaissance, man-in-the-middle attacks, or persistent access through compromised routers. While the vulnerability does not directly affect availability, the integrity and confidentiality of network management are at risk. Organizations with remote or web-accessible router management interfaces are particularly vulnerable. Given the widespread use of Linksys devices in both enterprise branch offices and home office environments across Europe, this vulnerability could be leveraged to target critical infrastructure, corporate networks, or teleworking setups. The medium severity indicates a moderate risk, but the potential for lateral movement and escalation within networks elevates the importance of addressing this issue promptly.

1. Immediately restrict access to the Linksys E5600 router management interface to trusted networks only, preferably via VPN or internal network segments. 2. Disable remote web management if not strictly necessary to reduce exposure. 3. Implement strict input validation and sanitization on the hostname and domainName parameters within the router firmware; if possible, update firmware once a patch is released. 4. Monitor router logs and network traffic for unusual activity or attempts to inject scripts. 5. Educate network administrators to avoid clicking on suspicious links or payloads that could trigger the stored XSS. 6. Use network segmentation to isolate critical devices and limit the impact of a compromised router. 7. Regularly audit and update router firmware to incorporate security patches as they become available. 8. Employ web application firewalls or intrusion detection systems to detect and block malicious payloads targeting router management interfaces.