CVE-2024-55374 identifies a username enumeration vulnerability in REDCap version 14.3.13, a widely used electronic data capture platform for research studies. The flaw arises because the application returns distinguishable responses or behaviors when login attempts are made with valid versus invalid usernames. This discrepancy allows an unauthenticated attacker to systematically test usernames and determine which ones exist in the system. Username enumeration is a critical reconnaissance step that can facilitate subsequent attacks such as credential stuffing, brute force password attacks, or social engineering. The vulnerability does not require prior authentication or user interaction, increasing its exploitability. Although no CVSS score has been assigned and no public exploits are known, the vulnerability is publicly disclosed and considered published. REDCap is commonly deployed in healthcare, academic, and research institutions, where protecting user identity and access credentials is essential. The lack of patch or mitigation details in the provided data suggests that organizations should proactively implement compensating controls. The vulnerability primarily impacts confidentiality by exposing valid usernames, while integrity and availability remain unaffected. The absence of a CVSS score necessitates a severity assessment based on impact and exploitability factors.

For European organizations, particularly those in healthcare, academic research, and clinical trial management, this vulnerability can lead to increased risk of targeted attacks. Username enumeration can enable attackers to identify valid user accounts, which can then be targeted for password guessing or phishing campaigns, potentially leading to unauthorized access to sensitive research data or personal health information. This could result in data breaches, regulatory non-compliance (e.g., GDPR violations), reputational damage, and operational disruptions. Since REDCap is widely used in European research institutions, the exposure of usernames could undermine trust in data confidentiality and complicate compliance with data protection laws. However, the vulnerability does not directly compromise system integrity or availability, limiting its impact to information disclosure and preparatory attack phases.

To mitigate this vulnerability, organizations should implement uniform error messages for login failures that do not reveal whether a username exists. Rate limiting and account lockout mechanisms should be enforced to prevent automated enumeration attempts. Multi-factor authentication (MFA) can reduce the risk of unauthorized access even if usernames are discovered. Network-level protections such as web application firewalls (WAFs) can detect and block suspicious login patterns indicative of enumeration. Organizations should monitor authentication logs for unusual activity and educate users about phishing risks. If possible, updating REDCap to a version where this issue is fixed is recommended once a patch is available. In the interim, applying custom patches or configuration changes to standardize login responses can reduce exposure. Regular security assessments and penetration testing should include checks for username enumeration vulnerabilities.