CVE-2021-47230
6.6 · MEDIUMOverview
CVE-2021-47230 is a medium-severity vulnerability affecting linux linux_kernel. It was published on May 21, 2024 and has a CVSS 3.1 base score of 6.6 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 6.6, rated MEDIUM. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.
Technical Description
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Immediately reset the MMU context when the SMM flag is cleared
Immediately reset the MMU context when the vCPU's SMM flag is cleared so
that the SMM flag in the MMU role is always synchronized with the vCPU's
flag. If RSM fails (which isn't correctly emulated), KVM will bail
without calling post_leave_smm() and leave the MMU in a bad state.
The bad MMU role can lead to a NULL pointer dereference when grabbing a
shadow page's rmap for a page fault as the initial lookups for the gfn
will happen with the vCPU's SMM flag (=0), whereas the rmap lookup will
use the shadow page's SMM flag, which comes from the MMU (=1). SMM has
an entirely different set of memslots, and so the initial lookup can find
a memslot (SMM=0) and then explode on the rmap memslot lookup (SMM=1).
general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in rang
Remediation
Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| linux | linux_kernel | >= 5.1, < 5.4.128 | Affected |
References
Frequently Asked Questions
What is CVE-2021-47230?
CVE-2021-47230 is a medium-severity vulnerability affecting linux linux_kernel. It was published on May 21, 2024 and has a CVSS 3.1 base score of 6.6 (MEDIUM).
How severe is CVE-2021-47230?
This vulnerability has a CVSS 3.1 base score of 6.6, rated MEDIUM. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2021-47230?
Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2021-47230?
CyberStrike's AI-powered security agents can automatically detect CVE-2021-47230 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
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