CVE-2023-4155
Published: September 13, 2023Last modified: September 15, 2023
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`).
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 5.6 |
| Attack Vector | LOCAL |
| Attack complexity | HIGH |
| Privileges required | LOW |
| User interaction | NONE |
| Scope | CHANGED |
| Confidentiality | NONE |
| Integrity impact | NONE |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:N/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | linux-lts | Not affected (6.1.50-r0) |
| Stream | linux-lts | Not affected (6.1.50-r0) |