CVE-2025-3849 is a medium-severity vulnerability identified in version 1.0 of the YXJ2018 SpringBoot-Vue-OnlineExam application, a web-based online examination system built using SpringBoot and Vue.js frameworks. The vulnerability resides in the /api/studentPWD endpoint, which handles password changes for student accounts. Specifically, the issue arises from improper validation of the studentId parameter, allowing an attacker to manipulate this argument to change passwords without proper verification or authentication. This flaw effectively bypasses standard security controls that should confirm the identity of the user requesting the password change. Since the vulnerability can be exploited remotely, an attacker does not require local access or prior authentication to initiate the attack. Although no public exploit is currently known to be actively used in the wild, the exploit details have been disclosed publicly, increasing the risk of exploitation by malicious actors. The vulnerability impacts the confidentiality and integrity of user accounts by enabling unauthorized password resets, potentially leading to account takeover, unauthorized access to sensitive examination data, and disruption of exam processes. The lack of authentication and verification in the password change mechanism represents a critical logic flaw in the application's security design. No official patches or fixes have been linked or published at this time, increasing the urgency for organizations using this software to implement compensating controls or mitigations.

For European organizations, particularly educational institutions and certification bodies relying on the YXJ2018 SpringBoot-Vue-OnlineExam platform, this vulnerability poses significant risks. Unauthorized password changes can lead to account takeovers of student profiles, enabling attackers to access personal data, exam results, and potentially manipulate exam submissions or schedules. This undermines the integrity of examination processes and could result in reputational damage, regulatory non-compliance (e.g., GDPR violations due to unauthorized data access), and operational disruptions. Additionally, compromised accounts could be leveraged as footholds for further attacks within organizational networks. The remote exploitability without authentication increases the threat level, especially in environments where the application is exposed to the internet without adequate network segmentation or access controls. The medium severity rating suggests moderate impact, but the real-world consequences could escalate depending on the scale of deployment and sensitivity of the data handled by the platform.

Given the absence of an official patch, European organizations should immediately implement the following specific mitigations: 1) Restrict access to the /api/studentPWD endpoint by enforcing network-level controls such as IP whitelisting or VPN-only access to limit exposure to trusted users. 2) Implement Web Application Firewall (WAF) rules to detect and block anomalous requests targeting the studentId parameter, including attempts to manipulate or inject unexpected values. 3) Conduct a thorough review and hardening of authentication and authorization logic around password management workflows, ensuring that password changes require verified identity confirmation, such as current password entry or multi-factor authentication (MFA). 4) Monitor application logs for unusual password change requests or patterns indicative of exploitation attempts. 5) Educate users and administrators about the vulnerability and encourage prompt reporting of suspicious account activity. 6) If feasible, temporarily disable self-service password reset/change features until a secure patch or update is available. 7) Engage with the vendor or development team to prioritize the release of a security patch addressing this flaw. 8) Consider deploying additional endpoint detection and response (EDR) tools to identify potential lateral movement or exploitation attempts stemming from compromised accounts.