Time-of-check Time-of-use (TOCTOU) Affecting kernel-rt-debug-modules package, versions <0:4.18.0-513.5.1.rt7.307.el8_9


Severity

Recommended
high

Based on CentOS security rating

    Threat Intelligence

    EPSS
    0.04% (11th percentile)

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  • Snyk ID SNYK-CENTOS8-KERNELRTDEBUGMODULES-5822332
  • published 7 Aug 2023
  • disclosed 4 Aug 2023

How to fix?

Upgrade Centos:8 kernel-rt-debug-modules to version 0:4.18.0-513.5.1.rt7.307.el8_9 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-rt-debug-modules package and not the kernel-rt-debug-modules package as distributed by Centos. See How to fix? for Centos:8 relevant fixed versions and status.

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 Scores

version 3.1
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NVD

5.6 medium
  • Attack Vector (AV)
    Local
  • Attack Complexity (AC)
    High
  • Privileges Required (PR)
    Low
  • User Interaction (UI)
    None
  • Scope (S)
    Changed
  • Confidentiality (C)
    None
  • Integrity (I)
    None
  • Availability (A)
    High
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Red Hat

5.3 medium
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SUSE

6.5 medium