- CISPA researchers reveal AMD CPU flaw “StackWarp” that breaks confidential VM protections
- Vulnerability enables RCE, privilege escalation, and private key theft in Zen processors
- AMD released 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 in virtual machines.
Cybersecurity researchers from the CISPA Helmholtz Center for Information Security in Germany detailed a vulnerability they called StackWarp, a hardware vulnerability in AMD CPUs that breaks the protection of confidential virtual machines by manipulating how the processor tracks the stack and allowing a malicious insider or hypervisor to change program in a protected VM data.
As a result, malicious actors can recover private keys and run code with elevated privileges, even though the VM’s memory should be secure.
Silver lining
StackWarp is said to affect AMD Zen processors, 1 through 5, with the researchers demonstrating the impact in several scenarios. In one case, they were able to reconstruct an RSE-2048 private key, while in another – they bypassed OpenSSH password authentication.
The neat thing about the report is that the malicious actor first needs privileged control over the host server running the virtual machines. This means that the vulnerability can be exploited by either malicious insiders, cloud providers or highly sophisticated threat actors with prior access.
This significantly reduces the number of potential attackers, but it still highlights how AMD’s SEV-SNP, designed to encrypt VM memory, can be weakened and compromised.
“These results show that CVM execution integrity – the very defense SEV-SNP aims to offer – can be effectively broken: confidential keys and passwords can be stolen, attackers can impersonate legitimate users or gain persistent control over the system, and isolation between guest VMs and the host or other VMs can no longer be trusted,” the report said.
AMD acknowledged the findings and released a patch, which the bug now tracked as CVE-2025-29943 and was given a low severity score (3.2/10).
Via The register
The best antivirus for all budgets
Follow TechRadar on Google News and add us as a preferred source to get our expert news, reviews and opinions in your feeds. Be sure to click the Follow button!
And of course you can too follow TechRadar on TikTok for news, reviews, video unboxings, and get regular updates from us on WhatsApp also.
