CVE-2024-54189 is a high-severity privilege escalation vulnerability affecting Parallels Desktop for Mac version 20.1.1 (build 55740). The vulnerability arises from the Snapshot functionality, where a root-level service writes to a file owned by a normal user. Due to improper handling of file operations, an attacker with limited privileges can exploit this by creating a hard link pointing to an arbitrary file. When the root service writes to the user-owned file, it inadvertently writes to the linked arbitrary file instead. This behavior allows an attacker to overwrite or modify files that normally require elevated privileges, effectively escalating their privileges to root. The underlying weakness is categorized under CWE-62 (Improper Restriction of Hard Links and Symbolic Links), which highlights insecure handling of filesystem links leading to potential security breaches. The CVSS v3.1 base score of 7.8 reflects the vulnerability's high impact on confidentiality, integrity, and availability, with low attack complexity and requiring only low privileges and no user interaction. Although no known exploits are currently reported in the wild, the vulnerability's nature and ease of exploitation make it a significant risk for affected users. The absence of an official patch at the time of reporting further increases the urgency for mitigation.

For European organizations using Parallels Desktop for Mac, particularly version 20.1.1, this vulnerability poses a serious risk. Successful exploitation can lead to full system compromise on affected Mac hosts, allowing attackers to gain root privileges. This can result in unauthorized access to sensitive data, modification or deletion of critical files, and disruption of virtual machine operations. Organizations relying on Parallels Desktop for development, testing, or production virtualization environments may face operational downtime and data breaches. The impact is especially critical in sectors with stringent data protection requirements such as finance, healthcare, and government agencies within Europe. Additionally, since the vulnerability allows privilege escalation from a local user context, insider threats or compromised user accounts could be leveraged to gain full control over systems. This undermines endpoint security and could facilitate lateral movement within corporate networks, increasing the overall attack surface and risk exposure.

To mitigate this vulnerability effectively, European organizations should: 1) Immediately identify and inventory all systems running Parallels Desktop for Mac version 20.1.1 (build 55740). 2) Restrict access to affected systems to trusted users only, minimizing the risk of local exploitation. 3) Implement strict file system permissions and monitor for suspicious hard link creations or modifications in directories used by Parallels snapshots. 4) Employ endpoint detection and response (EDR) tools configured to alert on unusual file system activities indicative of hard link exploitation. 5) Until an official patch is released, consider disabling or limiting the use of the snapshot functionality within Parallels Desktop to reduce attack vectors. 6) Maintain robust user account management, enforcing least privilege principles and strong authentication to reduce the likelihood of local user compromise. 7) Regularly check for updates from Parallels and apply security patches promptly once available. 8) Conduct security awareness training to inform users about the risks of local privilege escalation and safe usage practices of virtualization software.