CVE-2021-47664 is a vulnerability identified in the Franka Emika Robot, a robotic system developed by Franka Robotics. The core issue stems from an improper authentication mechanism that allows an unauthenticated remote attacker to enumerate valid usernames on the device. This vulnerability is classified under CWE-203, which refers to observable discrepancies that can be exploited to gain information about valid user accounts. Specifically, the flaw enables attackers to distinguish between valid and invalid usernames by analyzing differences in system responses or error messages during authentication attempts. This information disclosure does not require prior authentication or user interaction, making it remotely exploitable. Although the vulnerability does not directly allow unauthorized access or control of the robot, the ability to enumerate valid usernames can facilitate further targeted attacks such as brute force password attempts, social engineering, or privilege escalation. The affected product version is listed as 0.0.0, which likely indicates an early or initial release version of the Franka Emika Robot software. No patches or known exploits in the wild have been reported as of the publication date (April 24, 2025). The vulnerability was assigned by CERTVDE and is enriched by CISA, indicating recognition by major cybersecurity authorities. Given the nature of the flaw, it primarily impacts the confidentiality of user identity information and could serve as a stepping stone for more severe attacks if combined with other vulnerabilities or weak security practices.

For European organizations utilizing Franka Emika Robots, this vulnerability poses a moderate risk primarily related to information disclosure. The enumeration of valid usernames can undermine the confidentiality of user credentials and facilitate subsequent attacks such as password guessing or targeted phishing campaigns. In industrial or manufacturing environments where these robots are deployed, unauthorized access could lead to operational disruptions, intellectual property theft, or sabotage if attackers leverage enumerated usernames to gain control. Although the vulnerability itself does not allow direct control or manipulation of the robot, it lowers the barrier for attackers to compromise accounts with elevated privileges. This risk is particularly relevant for organizations relying on automated robotic systems for critical production processes, including automotive, aerospace, and electronics sectors prevalent in Europe. Additionally, the exposure of valid usernames could have privacy implications under GDPR if user identity information is linked to personal data. The absence of known exploits reduces immediate threat levels, but the vulnerability's presence in early software versions suggests that organizations running unpatched or legacy systems are at higher risk.

1. Implement network-level access controls to restrict remote access to the Franka Emika Robot management interfaces, limiting exposure to trusted internal networks only. 2. Employ strong password policies and account lockout mechanisms to mitigate the risk of brute force attacks following username enumeration. 3. Monitor authentication logs for unusual patterns indicative of enumeration or brute force attempts and establish alerting mechanisms. 4. Where possible, upgrade the robot's firmware or software to the latest version provided by Franka Robotics once patches become available. 5. Use multi-factor authentication (MFA) for all user accounts interacting with the robot to reduce the impact of compromised credentials. 6. Conduct regular security assessments and penetration tests focusing on authentication mechanisms to identify and remediate similar issues proactively. 7. Segregate robotic control networks from general IT networks to limit lateral movement opportunities for attackers. 8. Educate users and administrators about the risks of username enumeration and encourage vigilance against phishing or social engineering attacks that may leverage disclosed usernames.