CVE-2025-3966 is an information disclosure vulnerability identified in version 1.0.3 of the itwanger paicoding software, specifically within the Browsing History Handler component. The vulnerability arises from improper handling of requests to the endpoint /user/home with parameters such as userId=1 and homeSelectType=read. This flaw allows an unauthenticated remote attacker to manipulate the request and gain unauthorized access to sensitive information that should otherwise be protected. The vulnerability does not require user interaction or authentication, making it remotely exploitable over the network with low attack complexity. The CVSS 4.0 base score is 5.3 (medium severity), reflecting limited confidentiality impact with no direct effect on integrity or availability. The vulnerability is classified as problematic due to the potential leakage of user browsing history or related personal data, which could be leveraged for further attacks or privacy violations. Although no known exploits are currently observed in the wild, the public disclosure of the exploit code increases the risk of exploitation. No patches or fixes have been officially released at the time of publication, indicating that affected users remain vulnerable. The vulnerability does not involve privilege escalation or code execution but poses a risk to confidentiality by exposing sensitive user data through a web endpoint that is insufficiently protected.

For European organizations using itwanger paicoding 1.0.3, this vulnerability could lead to unauthorized disclosure of user browsing histories or other personal data managed by the application. This exposure can result in privacy breaches, non-compliance with GDPR regulations, and potential reputational damage. Organizations handling sensitive user information or operating in regulated sectors such as finance, healthcare, or government may face increased scrutiny and legal consequences if such data is leaked. While the vulnerability does not directly impact system integrity or availability, the confidentiality breach can be leveraged by attackers for social engineering, targeted phishing, or further infiltration. The medium severity rating suggests a moderate risk, but the ease of remote exploitation without authentication increases the urgency for mitigation. The lack of known active exploitation reduces immediate risk but does not eliminate the threat, especially given the public availability of exploit details.

Implement strict access controls on the /user/home endpoint, ensuring that userId parameters are validated against authenticated sessions to prevent unauthorized data access. Deploy web application firewalls (WAFs) with custom rules to detect and block suspicious requests targeting the Browsing History Handler, particularly those attempting to enumerate userIds or manipulate homeSelectType parameters. Conduct thorough code reviews and security testing of the paicoding application to identify and remediate similar information disclosure issues. Monitor application logs for unusual access patterns or repeated requests to the vulnerable endpoint, enabling early detection of exploitation attempts. If possible, upgrade to a patched version of paicoding once available; until then, consider disabling or restricting access to the vulnerable component to minimize exposure. Enforce network segmentation and limit external exposure of the paicoding service to trusted internal networks or VPNs to reduce attack surface. Educate users and administrators about the risks of information disclosure vulnerabilities and encourage prompt reporting of suspicious activity.