CVE-2025-54806 is a cross-site scripting (XSS) vulnerability identified in GROWI, Inc.'s GROWI product, specifically affecting versions 4.2.7 and earlier. The vulnerability resides in the page alert function, which improperly sanitizes user-supplied input embedded in URLs. When a logged-in user accesses a crafted URL containing malicious script code, the script executes within the user's browser context. This type of vulnerability allows attackers to bypass the same-origin policy, enabling them to steal session cookies, perform actions on behalf of the user, or manipulate the web interface. The CVSS 3.0 base score is 6.1, reflecting a medium severity level, with an attack vector of network (remote), low attack complexity, no privileges required, but requiring user interaction. The scope is changed, indicating the vulnerability affects components beyond the initially vulnerable part, and the impact affects confidentiality and integrity but not availability. No public exploits have been reported yet, but the vulnerability poses a risk especially in environments where GROWI is used for sensitive internal collaboration or documentation. The vulnerability highlights the need for proper input validation and output encoding in web applications to prevent script injection attacks.

For European organizations, this vulnerability could lead to unauthorized access to sensitive internal information, session hijacking, and potential lateral movement within corporate networks if exploited. Since GROWI is often used for internal knowledge management and collaboration, an attacker exploiting this XSS flaw could impersonate users, extract confidential data, or inject malicious content that spreads further within the organization. The impact is primarily on confidentiality and integrity, with no direct availability impact. Organizations in sectors with high regulatory requirements for data protection, such as finance, healthcare, and government, could face compliance risks and reputational damage if exploited. The requirement for user interaction limits mass exploitation but targeted phishing campaigns could effectively leverage this vulnerability. The absence of known exploits in the wild suggests a window for proactive mitigation before widespread attacks occur.

1. Upgrade GROWI to the latest version once the vendor releases a patch addressing CVE-2025-54806. 2. Until a patch is available, implement web application firewall (WAF) rules to detect and block suspicious URL patterns that may contain malicious scripts targeting the alert function. 3. Enforce Content Security Policy (CSP) headers to restrict the execution of inline scripts and reduce the impact of XSS attacks. 4. Conduct user awareness training focusing on phishing and social engineering risks, emphasizing caution when clicking on URLs even from trusted sources. 5. Review and harden input validation and output encoding mechanisms within GROWI customizations or integrations. 6. Monitor logs for unusual user activity or access patterns that may indicate exploitation attempts. 7. Consider isolating GROWI instances behind VPNs or internal networks to limit exposure to external attackers. 8. Regularly audit and update third-party dependencies and plugins used by GROWI to minimize additional attack surfaces.