CVE-2025-62624: Buffer Overflow in VMware ESXi

The heap-based buffer overflow vulnerability in VMware ESXi's ionic cloud driver presents a severe risk. An attacker who can exploit this flaw could achieve privilege escalation, potentially gaining root access to the ESXi host. This would allow them to execute arbitrary code, effectively compromising the entire system. The impact extends beyond the immediate host, as a compromised ESXi host can be used as a launchpad for lateral movement within the virtualized environment, potentially affecting other virtual machines and connected networks. The blast radius could be significant, depending on the network segmentation and security controls in place. This vulnerability shares characteristics with other memory corruption vulnerabilities that have led to full system compromise in the past.

1. Published2026-05-13

The primary mitigation for CVE-2025-62624 is to upgrade to a patched version of VMware ESXi or VCF as soon as it becomes available from VMware. Until a patch is available, consider implementing temporary workarounds to reduce the attack surface. Restrict network access to the ionic cloud driver service, limiting connections to trusted sources only. Implement strict firewall rules to control inbound and outbound traffic to the ESXi host. Monitor ESXi host logs for any suspicious activity related to the ionic cloud driver. While a rollback is not a direct mitigation, reverting to a previous, unpatched version before the vulnerability was introduced is an option if an upgrade is not immediately feasible, but carries its own risks. After upgrade, confirm the vulnerability is resolved by attempting a controlled exploit attempt in a non-production environment.