CVE-2023-4155

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`).

CVSS Metrics

• v3.1•MEDIUM•Score: 5.3CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:N/I:N/A:H
• v3.1•MEDIUM•Score: 5.6CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:N/A:H

EPSS Trends

Current EPSS score: 0.01%• Percentile: 2%

Techniques & Countermeasures

• CWE-367•Time-of-check Time-of-use (TOCTOU) Race Condition

  The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.

Affected Systems

• fedoraproject•fedora

  37 | 38

• linux•linux_kernel

  na

• redhat•enterprise_linux

  8.0 | 9.0

References (2)

• https://access.redhat.com/security/cve/CVE-2023-4155
• https://bugzilla.redhat.com/show_bug.cgi?id=2213802