CVE intelligence and bounded remediation

CVE-2023-4155 — A flaw was found in KVM AMD Secure Encrypted Virtualization (SEV) in the Linux kernel

Medium CVSS 5.6

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
Medium
CVSS
5.6 (3.1)
Published
2023-09-13
CISA KEV
Not currently listed
Ecosystem
linux/kernel
Weaknesses
CWE-367

Affected products

  • linux / linux_kernel
  • redhat / enterprise_linux / 8.0
  • redhat / enterprise_linux / 9.0
  • fedoraproject / fedora / 37
  • fedoraproject / fedora / 38

Matched remediation archetype

Race condition, TOCTOU, and lifecycle synchronization

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Map concurrent actors, shared state, lock boundaries, signals, callbacks, retries, and check-then-use sequences in the affected path.
  • Determine whether untrusted users can influence timing, object names, filesystem state, or repeated state transitions.
  • Identify clustered and multi-process behavior that repository-local tests may not represent.

Remediate safely

  • Make the sensitive state transition atomic or protect it with a consistently ordered synchronization primitive.
  • Perform authorization and invariant checks on the same authoritative object and transaction used for the operation.
  • Use unique private resources, safe ownership transfer, and idempotent operations; add deterministic concurrency regression tests.

Authoritative sources

Complete CVE record and remediation plan

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