CVE-2024-6154 is a heap-based buffer overflow vulnerability identified in the Toolgate component of Parallels Desktop version 18.2.0. The vulnerability arises due to insufficient validation of the length of user-supplied data before copying it into a fixed-length heap buffer. This improper validation allows an attacker who already has the ability to execute high-privileged code on the guest virtual machine to overflow the buffer, leading to memory corruption on the host system. The corrupted memory can be leveraged to escalate privileges and execute arbitrary code with the privileges of the current user on the host OS. The vulnerability is classified under CWE-122 (Heap-based Buffer Overflow) and was reported by the Zero Day Initiative (ZDI) as ZDI-CAN-20450. The CVSS v3.0 base score is 8.2, indicating high severity, with attack vector local, low attack complexity, high privileges required, no user interaction, and scope changed due to impact crossing from guest to host. No public exploits have been reported yet, but the potential for privilege escalation from guest to host makes this a critical concern for environments relying on Parallels Desktop virtualization.

The primary impact of CVE-2024-6154 is local privilege escalation from a compromised guest virtual machine to the host system, which can lead to full host compromise. This undermines the isolation guarantees typically provided by virtualization, potentially allowing attackers to bypass security controls and access sensitive host resources. Confidentiality is at risk as attackers could access host data, integrity is compromised through arbitrary code execution, and availability could be affected if attackers disrupt host operations. Organizations using Parallels Desktop for development, testing, or production virtualization environments face significant risks, especially if guest systems are accessible to untrusted users or exposed to malware. The vulnerability could facilitate lateral movement, persistence, and further exploitation within enterprise networks.

Until an official patch is released, organizations should implement strict access controls on guest virtual machines to limit the ability of users or processes to execute high-privileged code. Employ the principle of least privilege within guest OS environments to reduce the risk of initial compromise. Monitor guest and host systems for unusual behaviors indicative of exploitation attempts, such as unexpected privilege escalations or memory corruption events. Disable or restrict the use of the Toolgate component if feasible, or isolate critical workloads away from vulnerable Parallels Desktop instances. Once a patch is available, prioritize immediate deployment across all affected systems. Additionally, consider network segmentation to limit exposure of virtualized environments and employ endpoint detection and response (EDR) tools capable of detecting exploitation techniques related to heap-based buffer overflows.