CVE-2025-62650 is a vulnerability classified under CWE-603 (Use of Client-Side Authentication) affecting the Restaurant Brands International assistant platform. The platform relies on client-side authentication mechanisms to control access to its diagnostic screen, which is a critical security flaw. Client-side authentication means that the verification of user credentials or permissions occurs on the user's device or browser rather than on the server. This approach is inherently insecure because attackers can manipulate client-side controls, bypass authentication, and gain unauthorized access. The vulnerability affects all versions of the platform up to 2025-09-06. The CVSS v3.1 score of 8.3 reflects a high severity, with an attack vector of network (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), and a scope change (S:C). The impact includes partial loss of confidentiality, integrity, and availability, meaning attackers could view sensitive diagnostic data, alter system states, or disrupt operations. Although no known exploits are currently reported in the wild, the vulnerability poses a significant risk due to the ease of exploitation and the critical nature of the diagnostic screen in managing restaurant operations. The diagnostic screen likely provides access to system health, configuration, or troubleshooting tools, making unauthorized access a serious threat to operational security and data integrity.

For European organizations operating RBI’s assistant platform, this vulnerability could lead to unauthorized access to diagnostic functions, enabling attackers to gather sensitive operational data or disrupt restaurant management systems. This could result in compromised customer data, altered system configurations, or denial of service conditions affecting restaurant operations. The partial confidentiality impact may expose internal diagnostics or operational metrics, while integrity and availability impacts could allow attackers to manipulate system states or cause outages. Given the critical role of the assistant platform in supporting restaurant infrastructure, exploitation could lead to financial losses, reputational damage, and regulatory compliance issues, especially under GDPR if personal data is involved. The network-based attack vector and lack of required privileges or user interaction increase the risk of widespread exploitation if unpatched. European franchises and subsidiaries of RBI are particularly at risk, as the platform is likely integrated into their operational technology stack.

Immediate mitigation requires RBI to replace client-side authentication with robust server-side authentication and authorization controls for the diagnostic screen. This includes implementing secure session management, enforcing access control policies on the server, and validating all requests server-side. Organizations should monitor network traffic for unusual access patterns to the diagnostic interface and restrict access to trusted IP ranges or VPNs where possible. Applying network segmentation to isolate the diagnostic platform from public-facing networks can reduce exposure. RBI and affected organizations should prioritize patch development and deployment once available. In the interim, disabling or restricting access to the diagnostic screen can reduce risk. Conducting security audits and penetration testing focused on authentication mechanisms will help identify similar weaknesses. Training staff on the risks of client-side authentication and enforcing strict change management can prevent recurrence. Finally, organizations should maintain comprehensive logging and alerting to detect unauthorized access attempts promptly.