CVE-2025-62642 identifies a missing authorization vulnerability (CWE-862) in the Restaurant Brands International assistant platform, specifically in its signup API dubbed "Anyone Can Join This Party." This API fails to verify or authenticate user account creation requests, allowing any remote attacker to create user accounts without prior authorization or authentication. The vulnerability affects all versions up to 2025-09-06, with no patches currently available. The CVSS 3.1 base score is 5.8 (medium), reflecting that the attack vector is network-based (AV:N), requires no privileges (PR:N), no user interaction (UI:N), and impacts integrity (I:L) but not confidentiality or availability. The scope is changed (S:C), indicating that the vulnerability affects resources beyond the security scope of the vulnerable component. This flaw could be exploited to create fraudulent accounts, potentially enabling attackers to abuse platform features, escalate privileges, or conduct further attacks such as phishing or social engineering. Although no known exploits are reported in the wild, the vulnerability’s presence in a widely used restaurant assistant platform raises concerns about potential misuse. The lack of authorization checks on account creation is a fundamental security oversight that undermines the platform’s trust model and user management controls.

For European organizations, especially those operating or partnering with Restaurant Brands International or using its assistant platform, this vulnerability could lead to unauthorized account creation, undermining user trust and platform integrity. Fraudulent accounts might be used to manipulate loyalty programs, place unauthorized orders, or conduct social engineering attacks against legitimate users. This could result in financial losses, reputational damage, and increased operational costs due to fraud mitigation efforts. Additionally, attackers could leverage these unauthorized accounts as footholds for further attacks within the platform or associated systems. Given the platform’s role in customer interaction and order management, integrity issues could disrupt business processes. The impact is more pronounced in countries with high adoption of digital restaurant services and RBI’s market presence, where exploitation could affect a large user base and critical business operations.

To mitigate this vulnerability, organizations should immediately implement strict authorization and validation controls on the signup API to ensure only legitimate users can create accounts. This includes adding CAPTCHA challenges, email or phone verification, and rate limiting to prevent automated or bulk account creation. Monitoring and alerting on unusual signup patterns or spikes in account creation can help detect exploitation attempts early. Organizations should engage with Restaurant Brands International to obtain patches or updates addressing this issue and apply them promptly once available. Additionally, reviewing and tightening access controls and user privilege management within the platform can limit the potential damage from unauthorized accounts. Employing multi-factor authentication for sensitive actions and conducting regular security audits of user management APIs will further reduce risk. Finally, educating users and staff about potential social engineering risks stemming from fraudulent accounts can enhance overall security posture.