Cross-VM Network Channel Attacks and their Countermeasures in Cloud Computing Environments

Cloud providers enforce strict isolation between virtual machines (VMs) and user processes to ensure that co-located VMs remain separated. This approach creates an internal virtual network that segregates VMs sharing the same physical infrastructure. However, because these VMs rely on a shared Virtual Machine Monitor (VMM), virtual network, and hardware, they become vulnerable to cross-VM attacks. A malicious VM can exploit shared network connections, memory, and other resources—or even escalate privileges to infiltrate neighboring VMs. This research introduces two novel zero-day cross-VM network channel attacks. In the first attack, a malicious VM impersonates the Virtual Network Interface Controller (VNIC) to intercept and redirect network traffic from targeted VMs to a destination chosen by the attacker. Using readily available decryption tools such as Aircrack, the attacker can then extract sensitive, decrypted information from the intercepted data. The second attack demonstrates a privilege escalation vulnerability in a Xen hypervisor cloud environment. An adversary with limited access rights utilizes Return-Oriented Programming (ROP) to forge a connection with the root domain through the compromised network channel, thereby accessing the privileged tool stack. The study also proposes effective countermeasures to mitigate these vulnerabilities and enhance overall cloud security.