LiveActive security incident?Get immediate response
CVE Record

CVE-2021-47605: vduse: fix memory corruption in vduse_dev_ioctl()

In the Linux kernel, the following vulnerability has been resolved: vduse: fix memory corruption in vduse_dev_ioctl() The "config.offset" comes from the user. There needs to a check to prevent it being out of bounds. The "config.offset" and "dev->config_size" variables are both type u32. So if the offset if out of bounds then the "dev->config_size - config.offset" subtraction results in a very high u32 value. The out of bounds offset can result in memory corruption.

UnknownCVSS not scoredNot KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

This is a Linux kernel memory-corruption flaw in the VDUSE ioctl handling path. A user-controlled offset was not properly bounded, which could corrupt kernel memory. Business urgency depends on whether affected Linux 5.15-era kernels and VDUSE functionality are present.

Executive priority

Treat as a targeted kernel maintenance item until vendor scoring clarifies impact. Prioritize internet-facing, multi-tenant, virtualization, or untrusted-user systems running affected kernels. No cited source supports emergency active-exploitation response.

Technical view

In vduse_dev_ioctl(), config.offset is user controlled and typed as u32. Without an out-of-bounds check, subtracting it from dev->config_size can underflow to a very large u32 value, allowing an out-of-bounds operation and memory corruption.

Likely exposure

The source bundle identifies Linux kernel versions around 5.15, including 5.15.11 and 5.16, as affected. Exposure likely requires access to the VDUSE ioctl path. The sources do not define default enablement or privilege prerequisites.

Exploitation context

The provided sources do not report active exploitation, and KEV is false. They describe a memory-corruption condition from a user-controlled offset but do not provide exploitability details, impact scope, or attacker prerequisites.

Researcher notes

Evidence is limited to the CVE description and two Linux stable commits. The core bug is an unchecked u32 offset causing subtraction underflow and memory corruption. Missing data includes CVSS, CWE, privilege requirements, and practical impact.

Mitigation direction

  • Check vendor kernel advisories for CVE-2021-47605 coverage.
  • Update to a kernel build containing the referenced stable fixes.
  • Prioritize systems running affected 5.15-era Linux kernels.
  • Review whether VDUSE is present and operationally required.
  • Track distribution backports rather than relying only on upstream version numbers.

Validation and detection

  • Inventory Linux kernel versions across production and build images.
  • Confirm whether vendor packages include the referenced stable commits.
  • Review kernel configuration and runtime use of VDUSE.
  • Check vulnerability scanner findings against vendor backport status.
  • Document any systems awaiting vendor guidance or maintenance windows.
Prepared
Confidence
medium
Sources
4

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cve · low confidence lookup

CVE-2021-47605 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
3Timeline events
2ADP providers
3Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CVECVE Program Container
CISA-ADPCISA ADP Vulnrichment
other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinuxc8a6153b6c59d95c0e091f053f6f180952ade91e, c8a6153b6c59d95c0e091f053f6f180952ade91eunaffected
LinuxLinux5.15, 0, 5.15.11, 5.16affected
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.