CVE-2025-61113 identifies a security vulnerability in the TalkTalk 3.3.6 Android application, specifically involving improper access control across multiple API endpoints. This flaw allows attackers to modify request parameters to bypass intended access restrictions, thereby retrieving sensitive user information such as device identifiers and birthdays. Additionally, attackers can gain access to private group information, including join credentials, which are meant to be restricted. The vulnerability arises from insufficient validation and authorization checks on API requests, enabling unauthorized data disclosure and potential manipulation of group membership. Although no CVSS score has been assigned and no public exploits have been reported, the vulnerability poses a significant risk to user privacy and application integrity. The TalkTalk app is widely used in the UK and parts of Europe, making this a relevant threat to European users and organizations relying on this service. The lack of patch information suggests that remediation is pending or not publicly disclosed. Exploitation does not appear to require user interaction or authentication, increasing the attack surface. This vulnerability could be leveraged for targeted attacks aiming to harvest personal information or infiltrate private groups, potentially facilitating further malicious activities such as social engineering or unauthorized resource access.

The primary impact of CVE-2025-61113 is the compromise of user confidentiality and privacy through unauthorized disclosure of sensitive personal data, including device identifiers and birthdays. This can lead to identity theft, targeted phishing, or social engineering attacks. Access to private group information and join credentials further risks unauthorized participation in restricted communications or collaboration spaces, undermining organizational integrity and trust. For European organizations, especially those handling user data or providing services via the TalkTalk app, this vulnerability could result in regulatory non-compliance with GDPR due to data breaches. The exposure of device identifiers also raises concerns about device tracking and profiling. Although no availability impact is indicated, the breach of private group data could facilitate lateral movement or privilege escalation within organizational environments. The UK, with its significant TalkTalk user base, faces the highest risk, but other European countries where the app is used may also be affected. The absence of known exploits reduces immediate risk but does not eliminate the threat, especially if attackers develop tools to automate exploitation.

To mitigate CVE-2025-61113, TalkTalk should urgently implement strict access control mechanisms on all API endpoints, ensuring robust validation of request parameters and enforcing authentication and authorization checks. Application developers must conduct thorough code reviews and penetration testing focused on API security to identify and remediate similar flaws. Users should be advised to update the app promptly once a patch is released. Organizations should monitor network traffic for anomalous API requests indicative of parameter tampering and implement rate limiting to reduce abuse potential. Employing API gateways with built-in security policies can help enforce access restrictions. Additionally, logging and alerting on unauthorized access attempts will aid in early detection. From a compliance perspective, affected organizations should review data protection policies and prepare incident response plans addressing potential data breaches. Finally, educating users about phishing risks related to exposed personal data can reduce downstream exploitation.