CVE-2023-4155
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.
Does this matter?
Lower severity and a low EPSS score (0.17%). Track it; it rarely justifies an emergency change on its own.
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 3.1
- 5.6 MEDIUMCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:N/A:H
- EPSS
- 0.17% probability · 7th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-367
- Affected
- linux/linux kernel · redhat/enterprise linux · fedoraproject/fedora
- Source
- secalert@redhat.com
References
- https://access.redhat.com/security/cve/CVE-2023-4155Third Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2213802Issue Tracking, Patch, Third Party Advisory
- https://access.redhat.com/security/cve/CVE-2023-4155Third Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2213802Issue Tracking, Patch, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.