How severe is CVE-2021-47327?

CVE-2021-47327 has a CVSS 3.x base score of 7.1, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.

Is CVE-2021-47327 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-47327?

CVE-2021-47327 affects Linux Linux Kernel. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-47327?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2021-47327 have an EU (EUVD) identifier?

Yes. CVE-2021-47327 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-34332.

When was CVE-2021-47327 published?

CVE-2021-47327 was published on 2024-05-21 and last updated on 2026-06-17.

CVE-2021-47327

CVE-2021-47327 is a high-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 7.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-911.

Key facts

Severity: High (CVSS 3.x base score 7.1)
EPSS exploit prediction: 0% (17th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2021-34332
Weakness: CWE-911
Affected product: Linux Linux Kernel
Published: 2024-05-21
Last modified: 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: iommu/arm-smmu: Fix arm_smmu_device refcount leak when arm_smmu_rpm_get fails arm_smmu_rpm_get() invokes pm_runtime_get_sync(), which increases the refcount of the "smmu" even though the return value is less than 0. The reference counting issue happens in some error handling paths of arm_smmu_rpm_get() in its caller functions. When arm_smmu_rpm_get() fails, the caller functions forget to decrease the refcount of "smmu" increased by arm_smmu_rpm_get(), causing a refcount leak. Fix this issue by calling pm_runtime_resume_and_get() instead of pm_runtime_get_sync() in arm_smmu_rpm_get(), which can keep the refcount balanced in case of failure.

Frequently asked questions

What is CVE-2021-47327?: In the Linux kernel, the following vulnerability has been resolved: iommu/arm-smmu: Fix arm_smmu_device refcount leak when arm_smmu_rpm_get fails arm_smmu_rpm_get() invokes pm_runtime_get_sync(), which increases the refcount of the "smmu" even though the return value is less than 0. The reference counting issue happens in some error handling paths of arm_smmu_rpm_get() in its caller functions. When arm_smmu_rpm_get() fails, the caller functions forget to decrease the refcount of "smmu" increased by arm_smmu_rpm_get(), causing a refcount leak. Fix this issue by calling pm_runtime_resume_and_get() instead of pm_runtime_get_sync() in arm_smmu_rpm_get(), which can keep the refcount balanced in case of failure.
How severe is CVE-2021-47327?: CVE-2021-47327 has a CVSS 3.x base score of 7.1, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.
Is CVE-2021-47327 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-47327?: CVE-2021-47327 affects Linux Linux Kernel. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-47327?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2021-47327 have an EU (EUVD) identifier?: Yes. CVE-2021-47327 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-34332.
When was CVE-2021-47327 published?: CVE-2021-47327 was published on 2024-05-21 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

More vulnerabilities in Linux Linux Kernel

CVE-2023-2163 — Critical (CVSS 10.0): Incorrect verifier pruning in BPF in Linux Kernel >=5.4 leads to unsafe code paths being incorrectly marked as safe,…
CVE-2015-8104 — Critical (CVSS 10.0): The KVM subsystem in the Linux kernel through 4.2.6, and Xen 4.3.x through 4.6.x, allows guest OS users to cause a…
CVE-2015-1421 — Critical (CVSS 10.0): Use-after-free vulnerability in the sctp_assoc_update function in net/sctp/associola.c in the Linux kernel before…
CVE-2014-2523 — Critical (CVSS 10.0): net/netfilter/nf_conntrack_proto_dccp.c in the Linux kernel through 3.13.6 uses a DCCP header pointer incorrectly,…
CVE-2010-2495 — Critical (CVSS 10.0): The pppol2tp_xmit function in drivers/net/pppol2tp.c in the L2TP implementation in the Linux kernel before 2.6.34 does…
CVE-2010-2521 — Critical (CVSS 10.0): Multiple buffer overflows in fs/nfsd/nfs4xdr.c in the XDR implementation in the NFS server in the Linux kernel before…

All CVEs affecting Linux Linux Kernel →

Other CWE-911 vulnerabilities

CVE-2026-46316 — Critical (CVSS 9.3): In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: vgic-its: Drop the translation cache…
CVE-2026-46099 — High (CVSS 8.1): In the Linux kernel, the following vulnerability has been resolved: net: ipv6: fix NOREF dst use in seg6 and rpl…
CVE-2026-52943 — High (CVSS 7.8): In the Linux kernel, the following vulnerability has been resolved: net: skbuff: fix missing zerocopy reference in…
CVE-2024-46972 — High (CVSS 7.8): Software installed and run as a non-privileged user may conduct improper GPU system calls to trigger use-after-free…
CVE-2023-5633 — High (CVSS 7.8): The reference count changes made as part of the CVE-2023-33951 and CVE-2023-33952 fixes exposed a use-after-free flaw…
CVE-2022-29581 — High (CVSS 7.8): Improper Update of Reference Count vulnerability in net/sched of Linux Kernel allows local attacker to cause privilege…

Browse all CWE-911 vulnerabilities →