Host crash via unchecked CPUID entry count
Published Jan 9, 2020 · Updated Aug 5, 2024
An out-of-bounds write in Linux Kernel 3.13 through 5.4 allows local users to crash the host via a crafted KVM CPUID ioctl. In arch/x86/kvm/cpuid.c, the KVM_GET_EMULATED_CPUID path failed to check nent against maxnent before filling the variable-size entries array. Access to /dev/kvm on an x86 KVM host is required; the demonstrated consequence is a host kernel crash, not guest escape or attacker-controlled data corruption.
Summary
What happened
An out-of-bounds write in Linux Kernel 3.13 through 5.4 allows local users to crash the host via a crafted KVM CPUID ioctl. In arch/x86/kvm/cpuid.c, the KVM_GET_EMULATED_CPUID path failed to check nent against maxnent before filling the variable-size entries array. Access to /dev/kvm on an x86 KVM host is required; the demonstrated consequence is a host kernel crash, not guest escape or attacker-controlled data corruption.
The record
- CVE
- CVE-2019-19332
- Published
- Jan 9, 2020
- Updated
- Aug 5, 2024
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-787, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jan 9, 2020CVE publishedPublication date reported by the CVE source.
- Aug 5, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=3.13 through 5.4
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
- syzbot C reproducer for KVM CPUID out-of-bounds writeproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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