- CISPA Researchers Discover AMD CPU “StackWarp” Flaw Breaking Confidential Virtual Machine Protections
- Vulnerability allows RCE, privilege escalation and private key theft on Zen processors
- AMD released the patch (CVE-2025-29943), rated low severity, requiring host-level access to exploit
A recently discovered vulnerability in AMD chips allows malicious actors to perform remote code execution (RCE) and privilege escalation on virtual machines.
Cybersecurity researchers at the CISPA Helmholtz Center for Information Security in Germany detailed a vulnerability they called StackWarp, a hardware vulnerability in AMD CPUs that breaks the protections of sensitive virtual machines by manipulating the way the processor traces the stack and allowing a malicious insider or hypervisor to change program flow or read sensitive data within a protected VM.
As a result, malicious actors can retrieve private keys and execute highly privileged code, even though the VM’s memory was supposed to be secure.
Silver lining
StackWarp was said to affect AMD Zen processors, 1 through 5, and researchers demonstrated the impact in multiple scenarios. In one case, they were able to reconstruct a RSE-2048 private key, while in another, they bypassed OpenSSH password authentication.
The positive side of the report is the fact that the malicious actor first needs privileged control over the host server running the virtual machines. That means the vulnerability can be exploited by malicious insiders, cloud providers, or highly sophisticated threat actors with prior access.
This significantly reduces the number of potential attackers, but still highlights how AMD’s SEV-SNP, designed to encrypt virtual machine memory, can be weakened and compromised.
“These findings demonstrate that the execution integrity of CVM, the very defense that SEV-SNP is intended to provide, can be effectively broken: sensitive keys and passwords can be stolen, attackers can impersonate legitimate users or gain persistent control of the system, and the isolation between guest VMs and the host or other VMs can no longer be relied upon,” the report says.
AMD acknowledged the findings and released a patch, which the bug now tracks as CVE-2025-29943 and received a low severity score (3.2/10).
Through The Registry
The best antivirus for all budgets
Follow TechRadar on Google News and add us as a preferred source to receive news, reviews and opinions from our experts in your feeds. Be sure to click the Follow button!
And of course you can also follow TechRadar on TikTok for news, reviews, unboxings in video form and receive regular updates from us on WhatsApp also.
