CVE-2024-50592 is a time-of-check to time-of-use (TOCTOU) race condition vulnerability classified under CWE-367, found in the HASOMED Elefant Software Updater prior to version 1.4.2.1811. The vulnerability occurs during the repair or update process of the Elefant Update Service, which queries a server for a list of files and their hashes, including instructions to execute certain binaries to finalize the repair. These executables, such as PostESUUpdate.exe and Update_OpenJava.exe, are copied into a user-writable installation directory (C:\Elefant1) and then executed with NT AUTHORITY\SYSTEM privileges. Due to the race condition, an attacker with local access can overwrite these executables in the window between their copying and execution. Since the overwritten executables run with SYSTEM privileges, this allows the attacker to escalate their Windows user privileges from a low-privileged user to SYSTEM, effectively gaining full control over the affected machine. The attack requires local access and no user interaction, but the attacker must have at least low privileges on the system. The vulnerability impacts confidentiality, integrity, and availability by enabling full system compromise. Although no exploits have been reported in the wild, the vulnerability’s nature and high CVSS score (7.0) indicate a significant risk, especially in environments where local access is possible. The Elefant Software Updater is used in medical office environments, making healthcare organizations particularly sensitive targets. The vulnerability highlights the risks of improper handling of executable files in user-writable directories and the importance of secure update mechanisms.

For European organizations, especially those in the healthcare sector using HASOMED Elefant software, this vulnerability poses a critical risk. Successful exploitation allows an attacker with local access to gain SYSTEM-level privileges, leading to full control over affected systems. This can result in unauthorized access to sensitive patient data, manipulation or destruction of medical records, disruption of medical office operations, and potential violation of data protection regulations such as GDPR. The ability to escalate privileges locally also increases the risk of lateral movement within networks, potentially compromising broader organizational infrastructure. Given the critical nature of healthcare services, any disruption or data breach could have severe consequences for patient safety and organizational reputation. Additionally, the vulnerability could be leveraged to install persistent malware or ransomware, further amplifying the impact. The requirement for local access somewhat limits remote exploitation but does not eliminate risk, as insider threats or compromised user accounts could be leveraged. Overall, the vulnerability threatens confidentiality, integrity, and availability of critical healthcare IT systems in Europe.

To mitigate CVE-2024-50592, European organizations should implement the following specific measures: 1) Immediately restrict write permissions on the Elefant software installation directory (C:\Elefant1) to prevent unauthorized modification of executables by non-administrative users. 2) Monitor file system changes in the installation folder using endpoint detection and response (EDR) tools to detect suspicious overwrites or tampering attempts. 3) Enforce strict local user privilege management, limiting the number of users with local access and ensuring least privilege principles are applied. 4) Apply vendor patches or updates as soon as they become available to address the race condition vulnerability. 5) Implement application whitelisting to ensure only authorized executables can run with elevated privileges. 6) Conduct regular audits of local accounts and access logs to detect potential misuse or unauthorized access. 7) Educate staff about the risks of local privilege escalation and the importance of safeguarding local credentials. 8) Consider isolating medical office systems from general-purpose networks to reduce the risk of lateral movement. These steps go beyond generic advice by focusing on controlling the writable directory, monitoring for exploitation attempts, and enforcing strict local access controls tailored to the vulnerability’s exploitation vector.