Strix
26.1K

CVE-2023-4155

MEDIUMCVSS 5.6/10EPSS 0.16%

Last modified

CVE-2023-4155 is a medium-severity vulnerability rated 5.6/10 on the CVSS scale. A flaw was found in KVM AMD Secure Encrypted Virtualization (SEV) in the Linux kernel. A KVM guest using SEV-ES or SEV-SNP with multiple vCPUs can trigger a double fetch race condition vulnerability and invoke the `VMGEXIT` handler recursively. EPSS estimates a 0.16% chance of exploitation in the next 30 days.

Description

A flaw was found in KVM AMD Secure Encrypted Virtualization (SEV) in the Linux kernel. A KVM guest using SEV-ES or SEV-SNP with multiple vCPUs can trigger a double fetch race condition vulnerability and invoke the `VMGEXIT` handler recursively. If an attacker manages to call the handler multiple times, they can trigger a stack overflow and cause a denial of service or potentially guest-to-host escape in kernel configurations without stack guard pages (`CONFIG_VMAP_STACK`).

Metrics

CVSS 3.1
5.6/10

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:N/A:H

EPSS Probability
0.16%

5.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
LinuxLinux KernelAll versions
RedhatEnterprise Linux8.0
RedhatEnterprise Linux9.0
FedoraprojectFedora37
FedoraprojectFedora38

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2023-4155?
A flaw was found in KVM AMD Secure Encrypted Virtualization (SEV) in the Linux kernel. A KVM guest using SEV-ES or SEV-SNP with multiple vCPUs can trigger a double fetch race condition vulnerability and invoke the `VMGEXIT` handler recursively. If an attacker manages to call the handler multiple times, they can trigger a stack overflow and cause a denial of service or potentially guest-to-host escape in kernel configurations without stack guard pages (`CONFIG_VMAP_STACK`).
How severe is CVE-2023-4155?
CVE-2023-4155 has a CVSS score of 5.6/10 (MEDIUM severity). The EPSS model estimates a 0.16% probability of exploitation in the next 30 days.
How do I fix CVE-2023-4155?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2023-4155?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST