CVE-2025-7763 is an open redirect vulnerability found in thinkgem JeeSite versions up to 5.12.0, specifically within an unspecified function of the Site Controller/SSO component. Open redirect vulnerabilities occur when an application accepts untrusted input that causes it to redirect users to external, potentially malicious URLs without proper validation. This flaw allows remote attackers to craft URLs that appear legitimate but redirect users to attacker-controlled sites, facilitating phishing attacks, credential theft, or distribution of malware. The vulnerability does not require authentication and can be exploited remotely with user interaction (clicking a malicious link). Multiple endpoints in the affected component are vulnerable, increasing the attack surface. The vulnerability has been publicly disclosed with a patch identified by commit 3d06b8d009d0267f0255acc87ea19d29d07cedc3, though no known exploits are currently observed in the wild. The CVSS v4.0 score is 5.3 (medium severity), reflecting network attack vector, low complexity, no privileges or user interaction required for exploitation, and limited impact on integrity and availability but no impact on confidentiality. The vulnerability primarily impacts web applications using JeeSite for site management and single sign-on functionality, which are common in enterprise environments that rely on this framework for internal or customer-facing portals.

For European organizations using thinkgem JeeSite up to version 5.12.0, this vulnerability poses a moderate risk. Open redirect flaws can be leveraged in social engineering campaigns to redirect users to malicious websites, potentially leading to credential compromise or malware infection. This risk is heightened in sectors with high reliance on web portals for employee or customer access, such as finance, government, education, and healthcare. Although the vulnerability itself does not directly compromise system confidentiality or integrity, it undermines user trust and can serve as a stepping stone for more sophisticated attacks. The presence of multiple vulnerable endpoints increases the likelihood of successful exploitation. European organizations with public-facing JeeSite portals or internal SSO implementations should be particularly cautious, as attackers could exploit this vulnerability to bypass user awareness and deliver phishing payloads. The absence of known active exploits reduces immediate risk but does not eliminate the threat, especially given public disclosure and patch availability.

1. Apply the official patch identified by commit 3d06b8d009d0267f0255acc87ea19d29d07cedc3 immediately to all affected JeeSite instances to remediate the open redirect vulnerability. 2. Implement strict input validation and output encoding on all URL parameters used for redirection to ensure only trusted, whitelisted URLs are allowed. 3. Employ web application firewalls (WAFs) with rules designed to detect and block suspicious redirect patterns targeting JeeSite endpoints. 4. Conduct user awareness training focused on recognizing phishing attempts that exploit open redirects. 5. Monitor web server and application logs for unusual redirect requests or patterns indicative of exploitation attempts. 6. If patching is delayed, consider temporarily disabling or restricting access to the vulnerable Site Controller/SSO endpoints or implementing custom URL validation logic as a stopgap measure. 7. Regularly review and update security policies around third-party web frameworks and components to ensure timely vulnerability management.