CVE-2025-7763 is an open redirect vulnerability identified in thinkgem JeeSite, a Java-based web application framework widely used for rapid development of enterprise portals and content management systems. The vulnerability affects versions up to 5.12.0, specifically in the 'select' function of the SiteController component (src/main/java/com/jeesite/modules/cms/web/SiteController.java). The issue arises from improper validation or sanitization of the 'redirect' argument, allowing an attacker to manipulate this parameter to redirect users to arbitrary external URLs. This type of vulnerability is classified as an open redirect, which can be exploited remotely without authentication or privileges. The vulnerability has a CVSS 4.0 base score of 5.3 (medium severity), indicating a moderate risk. The attack vector is network-based (AV:N), requires no privileges (PR:N), and no user authentication (AT:N), but does require user interaction (UI:P), such as clicking a crafted link. The impact on confidentiality is none, integrity is low, and availability is none. The vulnerability does not compromise the server directly but can be leveraged for phishing, social engineering, or bypassing security controls like URL filters or same-origin policies. A patch has been released (commit 3d06b8d009d0267f0255acc87ea19d29d07cedc3) to address this issue by properly validating or restricting the redirect parameter. No known exploits are currently reported in the wild, but public disclosure means attackers could develop exploits soon.

For European organizations using thinkgem JeeSite, this vulnerability poses a moderate risk primarily related to user trust and phishing attacks. Attackers could craft malicious URLs that appear to originate from legitimate JeeSite-hosted domains, redirecting users to fraudulent websites to steal credentials, deliver malware, or conduct other social engineering attacks. This can lead to reputational damage, loss of customer trust, and potential regulatory scrutiny under GDPR if personal data is compromised as a result. Although the vulnerability does not directly compromise system integrity or availability, the indirect effects of successful phishing campaigns can be significant. Organizations in sectors with high reliance on web portals, such as government, education, and enterprise services, may be particularly impacted. The ease of exploitation and lack of required privileges increase the likelihood of exploitation attempts.

European organizations should prioritize applying the official patch (commit 3d06b8d009d0267f0255acc87ea19d29d07cedc3) provided by thinkgem as soon as possible to eliminate the open redirect vulnerability. In addition, organizations should implement strict input validation and whitelist-based URL redirection policies to ensure that redirect parameters only point to trusted internal URLs. Web application firewalls (WAFs) can be configured to detect and block suspicious redirect patterns. Security awareness training should be enhanced to educate users about the risks of clicking on unexpected links, especially those that appear to redirect through trusted domains. Regular security assessments and penetration testing should include checks for open redirect vulnerabilities. Monitoring web server logs for unusual redirect activities can help detect exploitation attempts early. Finally, organizations should review and update their incident response plans to address potential phishing campaigns leveraging this vulnerability.